Method of treatment or prophylaxis

ABSTRACT

The present invention is directed to methods and agents that are useful in the prevention and amelioration of signs and symptoms associated with neuropathic conditions. More particularly, the present invention discloses the use of angiotensin II receptor 2 (AT 2  receptor) antagonists for the treatment, prophylaxis, reversal and/or symptomatic relief of neuropathic pain, including mechanical hyperalgesia, thermal or mechanical allodynia, diabetic pain and entrapment pain, in vertebrate animals and particularly in human subjects. The AT 2  receptor antagonists may be provided alone or in combination with other compounds such as those that are useful in the control of neuropathic conditions.

This application is a continuation of U.S. application Ser. No.12/849,727, filed Aug. 3, 2010, which is a divisional application ofU.S. application Ser. No. 11/315,354, filed Dec. 23, 2005, now U.S. Pat.No. 7,795,275, which claims priority to Australian Application No.2004907332, filed Dec. 24, 2004, the contents of each of which arehereby incorporated by reference in their entireties.

FIELD OF THE INVENTION

This invention relates generally to compounds that are useful in theprevention and amelioration of signs and symptoms associated with aneuropathic condition. More particularly, the present invention relatesto the use of angiotensin II receptor 2 (AT₂ receptor) antagonists forthe treatment, prophylaxis, reversal and/or symptomatic relief ofneuropathic pain, including mechanical hyperalgesia, thermal ormechanical allodynia, diabetic pain and entrapment pain, in vertebrateanimals and particularly in human subjects. The AT₂ receptor antagonistsmay be provided alone or in combination with other compounds such asthose that are useful in the control of neuropathic conditions.

BACKGROUND OF THE INVENTION

Neuropathic pain may occur when the peripheral and/or central nervoussystems are sensitized following an injury to the peripheral nervoussystem or to the central nervous system. In contrast to the immediatepain (nociceptive pain) caused by tissue injury, neuropathic pain candevelop days or months after a traumatic injury and is frequentlylong-lasting or chronic. Moreover, neuropathic pain can occurspontaneously or as a result of stimulation that normally is notpainful. Neuropathic pain conditions are characterized by hyperesthesia(enhanced sensitivity to natural stimuli), hyperalgesia (abnormalsensitivity to pain), allodynia (widespread tenderness, characterized byhypersensitivity to tactile stimuli) and/or spontaneous burning pain.

The etiology of neuropathic pain is diverse and includes both trauma anddisease. For example, traumatic nerve compression or crush and traumaticinjury to the brain or spinal cord are common causes of neuropathicpain. Furthermore, traumatic nerve injuries may also cause the formationof neuromas, in which pain occurs as a result of aberrant nerveregeneration. In addition, cancer-related neuropathic pain is causedwhen tumor growth painfully compresses adjacent nerves, brain or spinalcord. Neuropathic pain also is associated with systemic diseases such asdiabetes, alcoholism, herpes zoster, AIDS/HIV, syphilis and variousother autoimmune diseases.

Although there are effective remedies for treating nociceptive pain,neuropathic pain is often resistant to available drug therapies. Inaddition, current therapies have serious side-effects including, forexample, cognitive changes, sedation, nausea and, in the case ofnarcotic drugs, tolerance and dependence. Many patients suffering fromneuropathic pain are elderly or have other medical conditions thatparticularly limit their ability to tolerate the side-effects associatedwith available drug therapy.

Accordingly, there is a need for the provision of agents that areeffective for treating and/or preventing the painful symptoms associatedwith neuropathic pain and with less undesirable side-effects.

SUMMARY OF THE INVENTION

Despite intensive investigations on the biological role of theangiotensin II type 2 receptor (AT₂ receptor) spanning over 15 years andmore than 2000 publications, there is no clear evidence of a therapeuticutility for this receptor (see, for example, the recent review bySteckelings et al. 2005, Peptides 26:1401-1409). Surprisingly, however,the present inventors have discovered that AT₂ receptor antagonists areeffective in the prevention or attenuation of the painful symptoms ofneuropathic conditions including primary and secondary neuropathies. Inone aspect, therefore, the invention provides methods for the treatmentor prophylaxis of a neuropathic condition in a subject. In someembodiments, the neuropathic condition is treated or prevented byadministering to the subject an effective amount of an AT₂ receptorantagonist. Non limiting examples of suitable AT₂ receptor antagonistsinclude small molecules, nucleic acids, peptides, polypeptides,peptidomimetics, carbohydrates, lipids or other organic (carboncontaining) or inorganic molecules, as further described herein.

The AT₂ receptor antagonist is suitably administered in the form of acomposition comprising a pharmaceutically acceptable carrier or diluent.The composition may be administered by injection, by topical applicationor by the oral route including sustained-release modes ofadministration, over a period of time and in amounts, which areeffective to treat or prevent the neuropathic condition. In someembodiments, the neuropathic condition results from a disease of thenerves (i.e., a primary neuropathy). In other embodiments, theneuropathic condition results from a systemic disease (i.e., secondaryneuropathy). In specific embodiments, the neuropathic condition is aperipheral neuropathic condition, especially that following mechanicalnerve injury or biochemical nerve injury such as painful diabeticneuropathy (PDN) or a related condition.

In accordance with the present invention, AT₂ receptor antagonists havebeen shown to prevent or attenuate the painful symptoms associated witha neuropathic condition. Thus, in another aspect, the invention providesmethods for preventing or attenuating neuropathic pain, especiallyperipheral neuropathic pain, in a subject. In some embodiments,neuropathic pain is prevented or attenuated by administering to thesubject an effective amount of an AT₂ receptor antagonist, which issuitably in the form of a composition comprising a pharmaceuticallyacceptable carrier and/or diluent.

In a related aspect, the invention provides methods for producinganalgesia in a subject, especially in a subject who has, or is at riskof developing, a neuropathic condition. These methods generally compriseadministering to the subject an effective amount of an AT₂ receptorantagonist, which is suitably in the form of a composition comprising apharmaceutically acceptable carrier and/or diluent.

In a further aspect, the present invention contemplates the use of anAT₂ receptor antagonist in the manufacture of a medicament for producinganalgesia in a subject, especially in a subject who has, or is at riskof developing, a neuropathic condition.

Any AT₂ receptor antagonist can be used in the compositions and methodsof the invention. In some embodiments, the AT₂ receptor antagonist isselected from compounds, and their pharmaceutically compatible salts,represented by the formula (I):

wherein:

-   -   R¹ and R² are independently selected from H, benzyl, substituted        benzyl, phenyl, substituted phenyl, C₁₋₆alkyl, substituted        C₁₋₆alkyl, C₃₋₆cycloalkyl, substituted C₃₋₆cycloalkyl, and        heteroaryl, providing that both R¹ and R² are not hydrogen,    -   R⁴ is selected from a carboxylate, carboxylic acid, sulfate,        phosphate, sulfonamide, phosphonamide or amide,    -   X is selected from CH, nitrogen, sulfur or oxygen with the        proviso that when X is sulfur or oxygen one of R¹ or R² is        absent,    -   Y is selected from sulfur, oxygen or N—R^(N), where R^(N) is        selected from H, C₁₋₆alkyl, substituted C₁₋₆alkyl, aryl,        substituted aryl, benzyl, substituted benzyl, C₁₋₄alkylaryl,        substituted C₁₋₄alkylaryl, OH, or NH₂,    -   G is a five or six membered, homoaromatic or unsaturated,        substituted or unsubstituted, heterocyclic ring including but        not limited to the following rings systems:

-   -   where the symbol ‘*’ indicates the bond shared between the fused        rings ‘A’ and ‘G’,    -   R⁵ is selected from H, C₁₋₆alkyl, phenyl, substituted phenyl,        substituted C₁₋₆alkyl, C₁₋₆alkoxy, or substituted C₁₋₆alkoxy,    -   R⁶ and R⁸ are independently selected from H, C₁₋₆alkyl,        substituted C₁₋₆alkyl, C₁₋₆alkoxy, substituted C₁₋₆alkoxy,        phenyl, phenyloxy, benzyl, benzyloxy, benzylamino, biphenyl,        substituted biphenyl, biphenyloxy, substituted biphenyloxy,        napthyl, substituted napthyl, provided that one of R⁶ or R⁸ is        not hydrogen, and    -   R⁷ is selected from phenyl, substituted phenyl, benzyl,        substituted benzyl, biphenyl, substituted biphenyl,        biphenylmethylene, substituted biphenyl methylene, napthyl,        substituted napthyl, napthylmethylene, and substituted        napthylmethylene.

In other embodiments, the AT₂ receptor antagonist is selected fromcompounds, and their pharmaceutically compatible salts, represented bythe formula (II):

wherein:

-   -   R¹ and R² are independently selected from H, phenyl, substituted        phenyl, benzyl, substituted benzyl, C₁₋₆alkyl, substituted        C₁₋₆alkyl, C₃₋₆cycloalkyl, substituted C₃₋₆cycloalkyl,        heteroaryl, and substituted heteroaryl, substituted        biphenylmethylene and saturated and unsaturated substituted        biphenylmethylene, provided that one of R¹ or R² is not        hydrogen,    -   R⁴ is selected from a carboxylate, carboxylic acid, sulfate,        phosphate, sulfonamide, phosphonamide or amide,    -   X is selected from CH, nitrogen, sulfur or oxygen with the        proviso that when X is sulfur or oxygen one of R¹ or R² is        absent, and    -   Y is selected from sulfur, oxygen or N—R^(N), where R^(N) is        selected from H, C₁₋₆alkyl, substituted C₁₋₆alkyl, aryl,        substituted aryl, benzyl, substituted benzyl, C₁₋₄alkylaryl,        substituted C₁₋₄alkylaryl, OH, or NH₂,

In still other embodiments, the AT₂ receptor antagonist is selected fromcompounds, and their pharmaceutically compatible salts, represented bythe formula (III):

wherein:

-   -   R¹, R² and R³ are independently selected from H, phenyl,        substituted phenyl, benzyl substituted benzyl, C₁₋₆alkyl,        substituted C₁₋₆alkyl, with the proviso that at least one of R¹        or R² are not hydrogen,    -   X is selected from CH, nitrogen, sulfur or oxygen with the        proviso that when X is sulfur or oxygen, one of R¹ or R² is        absent, or is aryl or heteroaryl with the proviso that both R¹        and R² are absent,    -   V is selected from CH or nitrogen atom,    -   Y is selected from sulfur, oxygen or N—R^(N), where R^(N) is        selected from H, C₁₋₆alkyl, substituted C₁₋₆alkyl, aryl,        substituted aryl, benzyl, substituted benzyl, C₁₋₄alkylaryl,        substituted C₁₋₄alkylaryl, OH, or NH₂,    -   R⁴ is selected from a carboxylate, carboxylic acid, sulfate,        phosphate, sulfonamide, phosphonamide, or amide,    -   G is a five or six membered, homoaromatic or unsaturated,        substituted or unsubstituted, heterocyclic ring including but        not limited to the following rings systems:

-   -   where the symbol indicates the bond shared between the fused        rings ‘A’ and ‘G’,    -   R⁵ is selected from H, C₁₋₆alkyl, phenyl, substituted phenyl,        substituted C₁₋₆alkyl, or C₁₋₆alkoxy,    -   R⁶ and R⁸ are independently selected from H, C₁₋₆alkyl,        substituted C₁₋₆alkyl C₁₋₆alkoxy, substituted, C₁₋₆alkoxy,        phenyl, phenyloxy, benzyl, benzyloxy, benzylamino, biphenyl,        substituted biphenyl, biphenyloxy, substituted biphenyloxy,        napthyl, substituted napthyl, provided that one of R⁶ or R⁸ is        not hydrogen, and    -   R⁷ is selected from phenyl, substituted phenyl, benzyl,        substituted benzyl, biphenyl, substituted biphenyl,        biphenylmethylene, substituted biphenylmethylene, napthyl,        substituted napthyl, napthylmethylene, and substituted        napthylmethylene.

In still other embodiments, the AT₂ receptor antagonist is selected fromcompounds, and their pharmaceutically compatible salts, represented bythe formula (IV):

wherein:

-   -   R¹⁰ is selected from H, halogen, C₁₋₆alkyl, phenyl, substituted        phenyl, substituted C₁₋₆alkyl, or C₁₋₆alkoxy,    -   R⁹ is selected from —NR¹³R¹⁴, wherein R¹³ and R¹⁴ are        independently selected from C₁₋₆alkyl, substituted C₁₋₆alkyl,        aryl, substituted aryl, benzyl, substituted benzyl,        C₁₋₄alkylaryl, substituted C₁₋₄alkylaryl, OH, or NH₂; a five or        six membered, saturated or unsaturated, substituted or        unsubstituted, carbocyclic or heterocyclic ring including but        not limited to:

-   -   V is selected from CH or a nitrogen atom,    -   Y is selected from sulfur, oxygen or N—R^(N), where R^(N) is        selected from H, C₁₋₆alkyl, substituted C₁₋₆alkyl, aryl,        substituted aryl, benzyl, substituted benzyl, C₁₋₄alkylaryl,        substituted C₁₋₄alkylaryl, OH, or NH₂,    -   G is a five or six membered homoaromatic or heterocyclic,        unsaturated, substituted ring including but not limited to the        following rings systems:

-   -   where the symbol ‘*’ indicates the bond shared between the fused        rings ‘A’ and ‘G’,    -   R⁵ is selected from C₁₋₆alkyl, phenyl, substituted phenyl,        substituted C₁₋₆alkyl, or C₁₋₆alkoxy,    -   W is selected from sulfur, oxygen or N—R^(N), where R^(N) is        selected from H, C₁₋₆alkyl, substituted C₁₋₆alkyl, aryl,        substituted aryl, benzyl, substituted benzyl, C₁₋₄alkylaryl,        substituted C₁₋₄alkylaryl, OH, or NH₂,    -   R⁶ and R⁸ are independently selected from H, C₁₋₆alkyl,        substituted C₁₋₆alkyl C₁₋₆alkoxy, substituted, C₁₋₆alkoxy,        phenyl, phenyloxy, benzyl, benzyloxy, benzylamino, biphenyl,        substituted biphenyl, biphenyloxy, substituted biphenyloxy,        napthyl, substituted napthyl, provided that one of R⁶ or R⁸ is        not hydrogen, and    -   R⁷ is selected from phenyl, substituted phenyl, benzyl,        substituted benzyl, biphenyl, substituted biphenyl,        biphenylmethylene, substituted biphenylmethylene, napthyl,        substituted napthyl, napthylmethylene, and substituted        napthylmethylene.

In still other embodiments, the AT₂ receptor antagonist is selected fromcompounds, and their pharmaceutically compatible salts, represented bythe formula (V):

wherein:

-   -   M is H or a halogen (fluoro, bromo, iodo, chloro),    -   R⁵ is selected from C₁₋₆alkyl, phenyl, substituted phenyl,        substituted C₁₋₆alkyl, or C₁₋₆alkoxy,    -   R¹⁶ is selected from C₁₋₆alkylamino, C₁₋₆dialkylamino,        substituted C₁₋₆alkylamino, substituted dialkylamino, arylamino,        diarylamino, substituted arylamino, substituted diarylamino,        alkylarylamino, dialkylarylamino, substituted alkylarylamino,        substituted dialkylarylamino, heteroarylamino, substituted        heteroarylamino, cycloalkylamino, dicycloalkylamino,        diheteroarylamino, alkylcarbonylamino, arylcarbonylamino,        alkylarylcarbonylamino, cycloalkylcarbonylamino, and    -   R¹⁷ is selected from C₁₋₆alkyl, substituted C₁₋₆alkyl, phenyl,        substituted phenyl, benzyl, substituted benzyl, biphenyl,        substituted biphenyl, biphenylmethylene, substituted        biphenylmethylene, naphthyl, substituted naphthyl, heteroaryl,        or substituted heteroaryl.

In further embodiments, the AT₂ receptor antagonist is selected from AT₂receptor antagonist peptides, illustrative examples of which includehexa-, hepta- and octapeptides, and their pharmaceutically compatiblesalts, represented by the formula:

R₁—R₂—R₃—R₄—R₅—R₆-Pro-R₇  (VIII)

wherein:

-   -   R₁ is absent or is selected from hydrogen, succinyl, L-aspartyl,        sarcosyl, L-seryl, succinamyl, L-propyl, glycyl, L-tyrosyl,        N_(α)-nicotinoyl-tyrosyl, or D- or L-asparagyl;    -   R₂ is selected from arginyl or N-benzoylcarbonyl arginyl;    -   R₃ is absent or valyl;    -   R₄ is absent or is selected from L-phenylalanyl or L-tyrosyl;    -   R₅ is selected from valyl, L-isoleucyl, L-alanyl or L-lysyl;    -   R₆ is selected from L-histidyl, L-isoleucyl, L-tyrosyl or        p-aminophenylalanyl; and    -   R₇ is selected from L-alanine, L-tyrosine, L- or D-leucine,        glycine, L-isoleucine or β-alanine residue.

In other embodiments, the AT₂ receptor antagonist is selected fromantigen-binding molecules that are immuno-interactive with an AT₂receptor polypeptide.

In still other embodiments, the AT₂ receptor antagonist is selected fromnucleic acid molecules that inhibit or otherwise reduce the level orfunctional activity of an expression product of an AT₂ receptor gene,illustrative examples of which include antisense molecules, ribozymesand RNAi molecules.

In yet another aspect, the invention provides methods for identifyingagents that antagonize an AT₂ receptor. These methods typically comprisecontacting a preparation with a test agent, wherein the preparationcomprises (i) a polypeptide comprising an amino acid sequencecorresponding to at least a biologically active fragment of an AT₂receptor polypeptide, or to a variant or derivative thereof; or (ii) apolynucleotide that comprises at least a portion of a genetic sequencethat regulates the expression of a gene that encodes an AT₂ receptorpolypeptide, wherein the polynucleotide is operably linked to a reportergene. A detected decrease in the level or functional activity of the AT₂receptor polypeptide, or an expression product of the reporter gene,relative to a normal or reference level or functional activity in theabsence of the test agent, indicates that the agent is an AT₂ receptorantagonist.

In some embodiments, the methods comprise contacting a first sample ofcells expressing an AT₂ receptor with an AT₂ receptor ligand andmeasuring a marker; contacting a second sample of cells expressing theAT₂ receptor with an agent and the ligand, and measuring the marker; andcomparing the marker of the first sample of cells with the marker of thesecond sample of cells. In illustrative examples, these methods measurethe levels of various markers (e.g., Zfhep expression; nitric oxidelevels or nitric oxide synthase levels) or combinations of markersassociated with the activation of the AT2 receptor or with theproliferation or differentiation of the cells. In these examples, anagent tests positive if it inhibits Zfhep expression or reduces thelevel of nitric oxide or the level or functional activity of nitricoxide synthase or the differentiation of the cells.

Still another aspect of the present invention provides methods ofproducing an agent for producing analgesia in a subject, especially in asubject who has, or is at risk of developing, a neuropathic condition.These methods generally comprise: testing an agent suspected ofantagonizing an AT₂ receptor, as broadly described above; andsynthesizing the agent on the basis that it tests positive for theantagonism. Suitably, the method further comprises derivatising theagent, and optionally formulating the derivatized agent with apharmaceutically acceptable carrier or diluent, to improve the efficacyof the agent for treating or preventing the neuropathic condition.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a graphical representation showing that single bolus doses ofintravenous (i.v.) PD-123,319 (0.1 & 0.3 mg/kg) produce dose-dependent(A) relief of tactile allodynia in the ipsilateral hindpaw of CCI-rats(n=2) and (B) antinociception in the contralateral hindpaw of the sameanimals.

FIG. 2 is a graphical representation showing that single bolus doses ofintraperitoneal (i.p.) PD-123,319 (1-10 mg/kg) produce dose-dependent(A) relief of tactile allodynia in the ipsilateral hindpaw of CCI-rats(n=3-4) and (B) antinociception in the contralateral hindpaw of the sameanimals. By contrast, i.p. administration of single bolus doses ofvehicle did not produce significant anti-allodynia or antinociception inthe ipsilateral and contralateral hindpaws respectively.

FIG. 3 is a graphical representation showing that single bolus doses ofi.v. L-159,686 (0.1-0.3 mg/kg) produce dose-dependent (A) relief oftactile allodynia in the ipsilateral hindpaw of CCI-rats (n=2) and (B)antinociception in the contralateral hindpaw of the same animals.

FIG. 4 is a graphical representation showing that single bolus doses ofi.p. PD-123,319 (0.3-3.0 mg/kg) produce dose-dependent relief of tactileallodynia in the hindpaws of STZ-diabetic rats (n=4). By contrast,single bolus doses of i.p. vehicle did not produce significant relief oftactile allodynia in the hindpaws of STZ-diabetic rats.

FIG. 5 is a graphical representation showing that single bolus i.p.doses of PD-121,981 (0.001-3 μg/kg) produce dose-dependent relief oftactile allodynia in STZ-diabetic rats.

FIG. 6 is a graphical representation showing that the extent andduration of the anti-allodynic effects produced by single bolus i.p. andoral doses of PD-121,981 (0.1 μg/kg) are similar for the two routes ofadministration in STZ-diabetic rats.

FIG. 7 is a graphical representation showing that single bolus i.p.doses of PD-126,055 (1.0-100 ng/kg) produced significant relief oftactile allodynia in STZ-diabetic rats.

FIG. 8 is a graphical representation showing that single bolus i.p.doses of L-161,638 (sodium salt) (0.0003-3 mg/kg) produce dose-dependentrelief of tactile allodynia in STZ-diabetic rats.

FIG. 9 is a graphical representation showing that single bolus i.p.doses of L-163,579 (0.1-10 μg/kg) produce dose-dependent relief oftactile allodynia in STZ-diabetic rats. Further increasing the dose ofL-163,579 (30-100 μg/kg) produce similar responses to those evoked bythe 10 μg/kg dose.

FIG. 10 is a graphical representation showing that single bolus i.p.doses of L-159,686 (0.03-10 μg/kg) produce dose-dependent relief oftactile allodynia in STZ-diabetic rats. Further increasing the dose to30 and 100 μg/kg did not appear to significantly alter the magnitude orthe duration of the anti-allodynic response.

FIG. 11 is a graphical representation showing that: (A) single i.p.bolus doses of PD-121,981 (0.03-3 mg/kg) produce dose-dependent reliefof tactile allodynia in the ipsilateral hindpaw of CCI-rats; and that(B) the same doses of PD-121,981 produces insignificant antinociceptionin the contralateral hindpaws of the same animals.

FIG. 12 is a graphical representation showing that the extent andduration of the anti-allodynic effects produced by single bolus i.p. andoral doses of PD-121,981 (1 mg/kg) are similar for the two routes ofadministration in CCI-rats.

FIG. 13 is a graphical representation showing that (A) single i.p. bolusdoses of PD-126,055 (3-30 μg/kg) produce dose-dependent relief oftactile allodynia in the ipsilateral hindpaw of CCI-rats. (B) Bycontrast, the same doses of PD-126,055 produced insignificantantinociception in the contralateral hindpaws of the same animals.

FIG. 14 is a graphical representation showing that the extent andduration of the anti-allodynic effects produced by single bolus i.p. andoral doses of PD-126,055 (30 μg/kg) are similar for the two routes ofadministration in CCI-rats.

FIG. 15 is a graphical representation showing that administration ofbolus i.p. doses of L-161,638 (sodium salt) (0.003-10 mg/kg) produced(A) dose-dependent relief of tactile allodynia in the ipsilateralhindpaw and (B) insignificant antinociception the contralateral hindpawof the same animals.

FIG. 16 is a graphical representation showing that administration ofbolus i.p. doses of L-163,579 (0.01-0.3 mg/kg) to CCI-rats produceddose-dependent relief of tactile allodynia in the ipsilateral hindpaw.

FIG. 17 is a graphical representation showing that administration ofbolus i.p. doses of L-159,686 (0.003-0.03 mg/kg) to CCI-rats produceddose-dependent relief of tactile allodynia in the ipsilateral hindpaw.

DETAILED DESCRIPTION OF THE INVENTION 1. Definitions

Unless defined otherwise, all technical and scientific terms used hereinhave the same meaning as commonly understood by those of ordinary skillin the art to which the invention belongs. Although any methods andmaterials similar or equivalent to those described herein can be used inthe practice or testing of the present invention, preferred methods andmaterials are described. For the purposes of the present invention, thefollowing terms are defined below.

The articles “a” and “an” are used herein to refer to one or to morethan one (i.e. to at least one) of the grammatical object of thearticle. By way of example, “an element” means one element or more thanone element.

As used herein, the term “about” refers to a quantity, level, value,dimension, size, or amount that varies by as much as 30%, 25%, 20%, 15%or 10% to a reference quantity, level, value, dimension, size, oramount.

Unless otherwise indicated, the term “acyl” denotes a group containingthe moiety C═O (and not being a carboxylic acid, ester or amide)Preferred acyl includes C(O)—R, wherein R is hydrogen or an alkyl,alkenyl, alkynyl, aryl, heteroaryl or heterocyclyl residue, preferably aC₁₋₂₀ residue. Examples of acyl include formyl; straight chain orbranched alkanoyl such as, acetyl, propanoyl, butanoyl,2-methylpropanoyl, pentanoyl, 2,2-dimethylpropanoyl, hexanoyl,heptanoyl, octanoyl, nonanoyl, decanoyl, undecanoyl, dodecanoyl,tridecanoyl, tetradecanoyl, pentadecanoyl, hexadecanoyl, heptadecanoyl,octadecanoyl, nonadecanoyl and icosanoyl; cycloalkylcarbonyl such ascyclopropylcarbonyl cyclobutylcarbonyl, cyclopentylcarbonyl andcyclohexylcarbonyl; aroyl such as benzoyl, toluoyl and naphthoyl;aralkanoyl such as phenylalkanoyl (e.g. phenylacetyl, phenylpropanoyl,phenylbutanoyl, phenylisobutanoyl, phenylpentanoyl and phenylhexanoyl)and naphthylalkanoyl (e.g. naphthylacetyl, naphthylpropanoyl andnaphthylbutanoyl]; aralkenoyl such as phenylalkenoyl (e.g.phenylpropenoyl, phenylbutenoyl, phenylmethacryloyl, phenylpentenoyl andphenylhexenoyl and naphthylalkenoyl (e.g. naphthylpropenoyl,naphthylbutenoyl and naphthylpentenoyl); aryloxyalkanoyl such asphenoxyacetyl and phenoxypropionyl; arylthiocarbamoyl such asphenylthiocarbamoyl; arylglyoxyloyl such as phenylglyoxyloyl andnaphthylglyoxyloyl; arylsulfonyl such as phenylsulfonyl andnapthylsulfonyl; heterocycliccarbonyl; heterocyclicalkanoyl such asthienylacetyl, thienylpropanoyl, thienylbutanoyl, thienylpentanoyl,thienylhexanoyl, thiazolylacetyl, thiadiazolylacetyl andtetrazolylacetyl; heterocyclicalkenoyl such as heterocyclicpropenoyl,heterocyclicbutenoyl, heterocyclicpentenoyl and heterocyclichexenoyl;and heterocyclicglyoxyloyl such as thiazolyglyoxyloyl andthienylglyoxyloyl.

If a number of carbon atoms is not specified, the term “alkenyl,” unlessotherwise indicated, refers to a non-aromatic hydrocarbon radical,straight, branched or cyclic, containing from 2 to 10 carbon atoms andat least one carbon to carbon double bond. Preferably one carbon tocarbon double bond is present, and up to four non-aromatic carbon-carbondouble bonds may be present. Thus, “C₂-C₆alkenyl” means an alkenylradical having from 2 to 6 carbon atoms. Alkenyl groups include, but arenot limited to, ethenyl, propenyl, butenyl, 2-methylbutenyl andcyclohexenyl. The straight, branched or cyclic portion of the alkenylgroup may contain double bonds and may be substituted if a substitutedalkenyl group is indicated.

As used herein, “alkenylene” refers to a straight, branched or cyclic,preferably straight or branched, bivalent aliphatic hydrocarbon group,preferably having from 2 to about 20 carbon atoms and at least onedouble bond, more preferably 2 to 12 carbons, even more preferably loweralkenylene. The alkenylene group is optionally substituted with one ormore “alkyl group substituents.” There may be optionally inserted alongthe alkenylene group one or more oxygen, sulfur or substituted orunsubstituted nitrogen atoms, where the nitrogen substituent is alkyl aspreviously described. Exemplary alkenylene groups include —CH═CH— CH═CH—and —CH═CH—CH₂—. The term “lower alkenylene” refers to alkenylene groupshaving 2 to 6 carbons. Preferred alkenylene groups are lower alkenylene,with alkenylene of 3 to 4 carbon atoms being particularly preferred.

The terms “alkoxy,” “alkenoxy,” “alkynoxy,” “aryloxy,” “heteroaryloxy,”“heterocyclyloxy” and “acyloxy” respectively denote alkyl, alkenyl,alkynyl aryl, heteroaryl, heterocyclyl and acyl groups as herein definedwhen linked by oxygen.

“Alkoxy,” unless otherwise indicated, represents either a cyclic ornon-cyclic alkyl group attached through an oxygen bridge. “Alkoxy”therefore encompasses the definitions of alkyl and cycloalkyl below. Forexample, alkoxy groups include but are not limited to methoxy, oxyethoxy, n-propyloxy, i-propyloxy, cyclopentyloxy and cyclohexyloxy.

As used herein, “alkyl” is intended to include both branched andstraight-chain saturated aliphatic hydrocarbon group and may have aspecified number of carbon atoms. For example, C₁-C₁₀, as in“C₁-C₁₀alkyl” is defined to include groups having 1, 2, 3, 4, 5, 6, 7,8, 9 or 10 carbons in linear or branched arrangement. For example,“C₁-C₁₀alkyl” specifically includes, but is not limited to, methyl,ethyl, n-propyl, i-propyl, n-butyl, t-butyl, i-butyl, pentyl, hexyl,heptyl, octyl, nonyl, decyl.

As used herein, “alkylene” refers to a straight, branched or cyclic,preferably straight or branched, bivalent aliphatic hydrocarbon group,preferably having from 1 to about 20 carbon atoms, more preferably 1 to12 carbons, even more preferably lower alkylene. The alkylene group isoptionally substituted with one or more “alkyl group substituents.”There may be optionally inserted along the alkylene group one or moreoxygen, sulfur or substituted or unsubstituted nitrogen atoms, where thenitrogen substituent is alkyl as previously described. Exemplaryalkylene groups include methylene (—C₂—), ethylene (—CH₂CH₂—), propylene(—(C₂)₃—), cyclohexylene (—C₆H₁₀—), methylenedioxy (—O—CH₂—O—) andethylenedioxy (−O—(CH₂)₂—O—). The term “lower alkylene” refers toalkylene groups having 1 to 6 carbons. Preferred alkylene groups arelower alkylene, with alkylene of 1 to 3 carbon atoms being particularlypreferred.

As used herein, “alkylidene” refers to a bivalent group, such as ═CR9R0,which is attached to one atom of another group, forming a double bond.Exemplary alkylidene groups are methylidene (═CH2) and ethylidene(═CHCH₃). As used herein, “arylalkylidene” refers to an alkylidene groupin which either R9 or R0 is and aryl group. As used herein,“diarylalkylidene” refers to an alkylidene group in which R9 and R0 areboth aryl groups. “Diheteroarylalkylidene” refers to an alkylidene groupin which R9 and R0 are both heteroaryl groups.

The term “alkynyl” refers to a hydrocarbon radical straight, branched orcyclic, containing from 2 to 10 carbon atoms and at least one carbon tocarbon triple bond. Up to three carbon-carbon triple bonds may bepresent. Thus, “C₂-C₆alkynyl” means an alkynyl radical having from 2 to6 carbon atoms. Alkynyl groups include, but are not limited to, ethynyl,propynyl, butynyl, 3-methylbutynyl and so on. The straight, branched orcyclic portion of the alkynyl group may contain triple bonds and may besubstituted if a substituted alkynyl group is indicated.

In certain instances, substituents may be defined with a range ofcarbons that includes zero, such as (C₀-C₆)alkylene-aryl. If aryl istaken to be phenyl, this definition would include phenyl itself as wellas, for example, —CH₂Ph, —CH₂CH₂Ph, CH(CH₃)CH₂CH(CH₃)Ph.

As used herein, “alkynylene” refers to a straight, branched or cyclic,preferably straight or branched, bivalent aliphatic hydrocarbon group,preferably having from 2 to about 20 carbon atoms and at least onetriple bond, more preferably 2 to 12 carbons, even more preferably loweralkynylene. The alkynylene group is optionally substituted with one ormore “alkyl group substituents.” There may be optionally inserted alongthe alkynylene group one or more oxygen, sulfur or substituted orunsubstituted nitrogen atoms, where the nitrogen substituent is alkyl aspreviously described. Exemplary alkynylene groups include —C≡C—C≡C—,—C≡C— and —C≡C—C₂—. The term “lower alkynylene” refers to alkynylenegroups having 2 to 6 carbons. Preferred alkynylene groups are loweralkynylene, with alkynylene of 3 to 4 carbon atoms being particularlypreferred.

The term “allodynia” as used herein refers to the pain that results froma non-noxious stimulus i.e. pain due to a stimulus that does notnormally provoke pain. Examples of allodynia include, but are notlimited to, cold allodynia, tactile allodynia (pain due to lightpressure or touch), and the like.

The term “analgesia” is used herein to describe states of reduced painperception, including absence from pain sensations as well as states ofreduced or absent sensitivity to noxious stimuli. Such states of reducedor absent pain perception are induced by the administration of apain-controlling agent or agents and occur without loss ofconsciousness, as is commonly understood in the art. The term analgesiaencompasses the term “antinociception”, which is used in the art as aquantitative measure of analgesia or reduced pain sensitivity in animalmodels.

As used herein, the term “antagonist” means an agent that decreases orinhibits the biological activity of an AT₂ gene (Agtr2 gene) or anexpression product thereof including an AT₂ receptor polypeptide.

As used herein, the term “AT₂ receptor” means an angiotensin II type 2receptor (AT₂) receptor polypeptide that can bind angiotensin II and/orone or more other ligands. The term “AT₂ receptor” encompassesvertebrate homologs of AT₂ receptor family members, including, but notlimited to, mammalian, reptilian and avian homologs. Representativemammalian homologs of AT₂ receptor family members include, but are notlimited to, murine and human homologs.

The term “anti-allodynia” is used herein to describe states of reducedpain perception, including absence from pain sensations as well asstates of reduced or absent sensitivity to non-noxious stimuli. Suchstates of reduced or absent pain perception are induced by theadministration of a pain-controlling agent or agents and occur withoutloss of consciousness, as is commonly understood in the art.

By “antigen-binding molecule” is meant a molecule that has bindingaffinity for a target antigen. It will be understood that this termextends to immunoglobulins, immunoglobulin fragments andnon-immunoglobulin derived protein frameworks that exhibitantigen-binding activity.

“Antigenic or immunogenic activity” refers to the ability of apolypeptide, fragment, variant or derivative according to the inventionto produce an antigenic or immunogenic response in an animal, suitably amammal, to which it is administered, wherein the response includes theproduction of elements which specifically bind the polypeptide orfragment thereof.

As used herein, “aromatic” or “aryl” is intended to mean, unlessotherwise indicated, any stable monocyclic or bicyclic carbon ring of upto 7 atoms in each ring, wherein at least one ring is aromatic. Examplesof such aryl elements include, but are not limited to, phenyl, naphthyl,tetrahydronaphthyl, indanyl, biphenyl, phenanthryl, anthryl oracenaphthyl.

“Aralkyl” means alkyl as defined above which is substituted with an arylgroup as defined above, e.g., —CH₂phenyl, —(CH₂)₂phenyl, —(CH₂)₃phenyl,—H₂CH(CH₃)CH₂phenyl, and the like and derivatives thereof.

As used herein, “arylene” refers to a monocyclic or polycyclic,preferably monocyclic, bivalent aromatic group, preferably having from 3to about 20 carbon atoms and at least one aromatic ring, more preferably3 to 12 carbons, even more preferably lower arylene. The arylene groupis optionally substituted with one or more “alkyl group substituents.”There may be optionally inserted around the arylene group one or moreoxygen, sulfur or substituted or unsubstituted nitrogen atoms, where thenitrogen substituent is alkyl as previously described. Exemplary arylenegroups include 1,2-, 1,3- and 1,4-phenylene. The term “lower arylene”refers to arylene groups having 5 or 6 carbons. Preferred arylene groupsare lower arylene.

As used herein, “arylidene” refers to an unsaturated cyclic bivalentgroup where both points of attachment are on the same atom of the ring.Exemplary arylidene groups include, but are not limited to, quinonemethide moieties that have the formula:

where X is O, S or NR9. “Heteroarylidene” groups are arylidene groupswhere one or two, preferably two, of the atoms in the ring areheteroatoms, such as, but not limited to, O, S and N.

As used herein, the term “biological activity” means any observableeffect flowing from the interaction between an AT₂ receptor polypeptideand a ligand. Representative, but non-limiting, examples of biologicalactivity in the context of the present invention include association ofan AT₂ receptor with a ligand, including an endogenous ligand such asangiotensin II or an AT₂ receptor antagonist. The term “biologicalactivity” also encompasses both the inhibition and the induction of theexpression of an AT₂ receptor polypeptide. Further, the term “biologicalactivity” encompasses any and all effects flowing from the binding of aligand by an AT₂ receptor polypeptide.

The term “causalgia” as used herein refers to the burning pain,allodynia, and hyperpathia after a traumatic nerve lesion, oftencombined with vasomotor and sudomotor dysfunction and later trophicchanges.

By “complex regional pain syndromes” is meant the pain that includes,but is not limited to, reflex sympathetic dystrophy, causalgia,sympathetically maintained pain, and the like.

Throughout this specification, unless the context requires otherwise,the words “comprise”, “comprises” and “comprising” will be understood toimply the inclusion of a stated step or element or group of steps orelements but not the exclusion of any other step or element or group ofsteps or elements.

By “corresponds to” or “corresponding to” is meant (a) a polynucleotidehaving a nucleotide sequence that is substantially identical orcomplementary to all or a portion of a reference polynucleotide sequenceor encoding an amino acid sequence identical to an amino acid sequencein a peptide or protein; or (b) a peptide or polypeptide having an aminoacid sequence that is substantially identical to a sequence of aminoacids in a reference peptide or protein.

The term “cycloalkenyl” means a monocyclic unsaturated hydrocarbon groupand may have a specified number of carbon atoms. For example,“cycloalkenyl” includes but is not limited to, cyclobutenyl,cyclopentenyl, 1-methylcyclopentenyl, cyclohexenyl and cyclohexadienyl.

Unless otherwise indicated, the term “cycloalkyl” or “aliphatic ring”means a monocyclic saturated aliphatic hydrocarbon group and may have aspecified number of carbon atoms. For example, “cycloalkyl” includes,but is not limited to, cyclopropyl, methyl-cyclopropyl,2,2-dimethyl-cyclobutyl, 2-ethyl-cyclopentyl, cyclohexyl.

By “derivative,” as applied to peptides and polypeptides, refers to apeptide or polypeptide that has been derived from the basic sequence bymodification, for example by conjugation or complexing with otherchemical moieties or by post-translational modification techniques aswould be understood in the art. The term “derivative” also includeswithin its scope alterations that have been made to a parent sequenceincluding additions or deletions that provide for functional equivalentmolecules.

By “effective amount”, in the context of treating or preventing acondition is meant the administration of that amount of active to anindividual in need of such treatment or prophylaxis, either in a singledose or as part of a series, that is effective for the prevention ofincurring a symptom, holding in check such symptoms, and/or treatingexisting symptoms, of that condition. The effective amount will varydepending upon the health and physical condition of the individual to betreated, the taxonomic group of individual to be treated, theformulation of the composition, the assessment of the medical situation,and other relevant factors. It is expected that the amount will fall ina relatively broad range that can be determined through routine trials.

The term “gene” as used herein refers to any and all discrete codingregions of the cell's genome, as well as associated non-coding andregulatory regions. The gene is also intended to mean the open readingframe encoding specific polypeptides, introns, and adjacent 5′ and 3′non-coding nucleotide sequences involved in the regulation ofexpression. In this regard, the gene may further comprise controlsignals such as promoters, enhancers, termination and/or polyadenylationsignals that are naturally associated with a given gene, or heterologouscontrol signals. The DNA sequences may be cDNA or genomic DNA or afragment thereof. The gene may be introduced into an appropriate vectorfor extrachromosomal maintenance or for integration into the host.

As appreciated by those of skill in the art, “halo” or “halogen” as usedherein is intended to include chloro, fluoro, bromo and iodo.

“Heteroaralkyl” group means alkyl as defined above which is substitutedwith a heteroaryl group, e.g., —CH₂pyridinyl, —(CH₂)₂pyrimidinyl,—(CH₂)₃imidazolyl, and the like, and derivatives thereof.

The term “heteroaryl” or “heteroaromatic,” as used herein, represents astable monocyclic or bicyclic ring of up to 7 atoms in each ring,wherein at least one ring is aromatic and contains from 1 to 4heteroatoms selected from the group consisting of O, N and S. Heteroarylgroups within the scope of this definition include but are not limitedto: acridinyl, carbazolyl, cinnolinyl, quinoxalinyl, pyrrazolyl,indolyl, benzotriazolyl, furanyl, thienyl, benzothienyl, bezofuranyl,quinolinyl, isoquinolinyl, oxazolyl, isoxazolyl, indolyl, pyrazinyl,pyridazinyl, pyridinyl, pyrimidinyl, pyrrolyl, tetrahydroquinoline. Aswith the definition of heterocycle below, “heteroaryl” is alsounderstood to include the N-oxide derivative of any nitrogen-containingheteroaryl.

Further examples of “heteroaryl” and “heterocyclyl” include, but are notlimited to, the following: benzoimidazolyl, benzofuranyl,benzofurazanyl, benzopyrazolyl, benzotriazolyl, benzothiophenyl,benzoxazolyl, carbazolyl, carbolinyl, cinnolinyl, furanyl, imidazoyl,indolinyl, indolyl, indolazinyl, indazolyl, isobenzofuranyl, isoindolyl,isoquinolyl, isothiazolyl, isoxazolyl, naphthpyridinyl, oxadiazolyl,oxazolyl, oxazoline, isoxazoline, oxetanyl, pyranyl, pyrazinyl,pyrazolyl, pyridazinyl, pyridopyridinyl, pyridazinyl, pyridyl,pyrimidyl, pyrrolyl, quinazolinyl, quinolyl, quinoxalinyl,tetrahydropyranyl, tetrazolyl, tetrazolopyridyl, thiadiazolyl,thiazolyl, thienyl, triazolyl, azetidinyl, aziridinyl, 1,4-dioxanyl,hexahydroazepinyl, piperazinyl, piperidinyl, pyrrolidinyl, morpholinyl,thiomorpholinyl, dihydrobenzoimidazolyl, dihydrobenzofuranyl,dihydrobenzothiophenyl, dihydrobenzoxazolyl, dihydrofuranyl,dihydroimidazolyl, dihydroindolyl, dihydroisooxazolyl,dihydroisothiazolyl, dihydrooxadiazolyl, dihydrooxazolyl,dihydropyrazinyl, dihydropyrazolyl, dihydropyridinyl,dihydropyrimidinyl, dihydropyrrolyl, dihydroquinolinyl,dihydrotetrazolyl, dihydrothiadiazolyl, dihydrothiazolyl,dihydrothienyl, dihydrotriazolyl, dihydroazetidinyl,methylenedioxybenzoyl, tetrahydrofuranyl, and tetrahydrothienyl, andN-oxides thereof. Attachment of a heterocyclyl substituent can occur viaa carbon atom or via a heteroatom.

As used herein, “heteroarylene,” unless otherwise indicated, refers to abivalent monocyclic or multicyclic ring system, preferably of about 3 toabout 15 members where one or more, more preferably 1 to 3 of the atomsin the ring system is a heteroatom, that is, an element other thancarbon, for example, nitrogen, oxygen and sulfur atoms. Theheteroarylene group may be optionally substituted with one or more,preferably 1 to 3, aryl group substituents. Exemplary heteroarylenegroups include, for example, 1,4-imidazolylene.

The term “heterocycle”, “heteroaliphatic” or “heterocyclyl” as usedherein is intended to mean a 5- to 10-membered nonaromatic heterocyclecontaining from 1 to 4 heteroatoms selected from the group consisting ofO, N and S, and includes bicyclic groups.

“Heterocyclylalkyl” group means alkyl as defined above which issubstituted with a heterocycle group, e.g., —CH₂pyrrolidin-1-yl,—(CH₂)₂piperidin-1-yl, and the like, and derivatives thereof.

“Hybridization” is used herein to denote the pairing of complementarynucleotide sequences to produce a DNA-DNA hybrid or a DNA-RNA hybrid.Complementary base sequences are those sequences that are related by thebase-pairing rules. In DNA, A pairs with T and C pairs with G. In RNA Upairs with A and C pairs with G. In this regard, the terms “match” and“mismatch” as used herein refer to the hybridization potential of pairednucleotides in complementary nucleic acid strands. Matched nucleotideshybridize efficiently, such as the classical A-T and G-C base pairmentioned above. Mismatches are other combinations of nucleotides thatdo not hybridize efficiently.

The term “hydrocarbyl” as used herein includes any radical containingcarbon and hydrogen including saturated, unsaturated, aromatic, straightor branched chain or cyclic including polycyclic groups. Hydrocarbylincludes but is not limited to C₁-C₈alkyl, C₂-C₈alkenyl, C₂-C₈alkynyl,C₂-C₁₀cycloalkyl, aryl such as phenyl and naphthyl, Ar (C₁-C₈)alkyl suchas benzyl, any of which may be optionally substituted.

By “hyperalgesia” is meant an increased response to a stimulus that isnormally painful.

Reference herein to “immuno-interactive” includes reference to anyinteraction, reaction, or other form of association between moleculesand in particular where one of the molecules is, or mimics, a componentof the immune system.

By “neuropathic pain” is meant any pain syndrome initiated or caused bya primary lesion or dysfunction in the peripheral or central nervoussystem. Examples of neuropathic pain include, but are not limited to,thermal or mechanical hyperalgesia, thermal or mechanical allodynia,diabetic pain, entrapment pain, and the like.

“Nociceptive pain” refers to the normal, acute pain sensation evoked byactivation of nociceptors located in non-damaged skin, viscera and otherorgans in the absence of sensitization.

The term “oligonucleotide” as used herein refers to a polymer composedof a multiplicity of nucleotide residues (deoxyribonucleotides orribonucleotides, or related structural variants or synthetic analoguesthereof) linked via phosphodiester bonds (or related structural variantsor synthetic analogues thereof). Thus, while the term “oligonucleotide”typically refers to a nucleotide polymer in which the nucleotideresidues and linkages between them are naturally occurring, it will beunderstood that the term also includes within its scope variousanalogues including, but not restricted to, peptide nucleic acids(PNAs), phosphoramidates, phosphorothioates, methyl phosphonates,2-O-methyl ribonucleic acids, and the like. The exact size of themolecule can vary depending on the particular application. Anoligonucleotide is typically rather short in length, generally fromabout 10 to 30 nucleotide residues, but the term can refer to moleculesof any length, although the term “polynucleotide” or “nucleic acid” istypically used for large oligonucleotides.

By “operably linked” is meant that transcriptional and translationalregulatory polynucleotides are positioned relative to apolypeptide-encoding polynucleotide in such a manner that thepolynucleotide is transcribed and the polypeptide is translated.

The term “pain” as used herein is given its broadest sense and includesan unpleasant sensory and emotional experience associated with actual orpotential tissue damage, or described in terms of such damage andincludes the more or less localized sensation of discomfort, distress,or agony, resulting from the stimulation of specialized nerve endings.There are many types of pain, including, but not limited to, lightningpains, phantom pains, shooting pains, acute pain, inflammatory pain,neuropathic pain, complex regional pain, neuralgia, neuropathy, and thelike (Dorland's Illustrated Medical Dictionary, 28^(th) Edition, W. B.Saunders Company, Philadelphia, Pa.). The present invention isparticularly concerned with the alleviation of pain associated withneuropathic conditions. The goal of treatment of pain is to reduce thedegree of severity of pain perceived by a treatment subject.

By “pharmaceutically acceptable carrier” is meant a solid or liquidfiller, diluent or encapsulating substance that may be safely used intopical, local or systemic administration.

The terms “pharmaceutically compatible salt” and “pharmaceuticallyacceptable salt” are used interchangeably herein to refer to a saltwhich is toxicologically safe for human and animal administration. Thissalt may be selected from a group including hydrochlorides,hydrobromides, hydroiodides, sulfates, bisulfates, nitrates, citrates,tartrates, bitartrates, phosphates, malates, maleates, napsylates,fumarates, succinates, acetates, terephthalates, pamoates andpectinates. Pharmaceutically acceptable salts include both the metallic(inorganic) salts and organic salts; a non-exhaustive list of which isgiven in Remington's Pharmaceutical Sciences 17th Edition, pg. 1418(1985). It is well known to one skilled in the art that an appropriatesalt form is chosen based on physical and chemical stability,flowability, hydroscopicity and solubility.

“Phenylalkyl” means alkyl as defined above which is substituted withphenyl, e.g., —CH₂phenyl, —(CH₂)₂phenyl, —(CH₂)₃phenyl,CH₃CH(CH₃)CH₂phenyl, and the like and derivatives thereof. Phenylalkylis a subset of the aralkyl group.

The terms “polynucleotide variant” and “variant” refer topolynucleotides displaying substantial sequence identity with areference polynucleotide sequence or polynucleotides that hybridize witha reference sequence under stringent conditions as known in the art (seefor example Sambrook et al., Molecular Cloning. A Laboratory Manual”,Cold Spring Harbor Press, 1989). These terms also encompasspolynucleotides in which one or more nucleotides have been added ordeleted, or replaced with different nucleotides. In this regard, it iswell understood in the art that certain alterations inclusive ofmutations, additions, deletions and substitutions can be made to areference polynucleotide whereby the altered polynucleotide retains abiological function or activity of the reference polynucleotide. Theterms “polynucleotide variant” and “variant” also includenaturally-occurring allelic variants.

“Polypeptide”, “peptide” and “protein” are used interchangeably hereinto refer to a polymer of amino acid residues and to variants andsynthetic analogues of the same. Thus, these terms apply to amino acidpolymers in which one or more amino acid residues is a syntheticnon-naturally occurring amino acid, such as a chemical analogue of acorresponding naturally occurring amino acid, as well as to naturallyoccurring amino acid polymers.

The term “polypeptide variant” refers to polypeptides in which one ormore amino acids have been replaced by different amino acids. It is wellunderstood in the art that some amino acids may be changed to otherswith broadly similar properties without changing the nature of theactivity of the polypeptide (conservative substitutions) as describedhereinafter. These terms also encompass polypeptides in which one ormore amino acids have been added or deleted, or replaced with differentamino acids.

The term “prodrug” is used in its broadest sense and encompasses thosecompounds that are converted in vivo to an AT₂ receptor antagonistaccording to the invention. Such compounds would readily occur to thoseof skill in the art, and include, for example, compounds where a freehydroxy group is converted into an ester derivative.

As used herein, “pseudohalides” are groups that behave substantiallysimilar to halides. Such groups can be used in the same manner andtreated in the same manner as halides (X, in which X is a halogen, suchas Cl or Br). Pseudohalides include, but are not limited to cyanide,cyanate, thiocyanate, selenocyanate, trifluoromethyl and azide.

The terms “subject” or “individual” or “patient”, used interchangeablyherein, refer to any subject, particularly a vertebrate subject, andeven more particularly a mammalian subject, for whom therapy orprophylaxis is desired. Suitable vertebrate animals that fall within thescope of the invention include, but are not restricted to, primates,avians, livestock animals (e.g., sheep, cows, horses, donkeys, pigs),laboratory test animals (e.g., rabbits, mice, rats, guinea pigs,hamsters), companion animals (e.g., cats, dogs) and captive wild animals(e.g., foxes, deer, dingoes). A preferred subject is a human in need oftreatment or prophylaxis for a neuropathic condition. However, it willbe understood that the aforementioned terms do not imply that symptomsare present.

“Stereoisomers” refer to any two or more isomers that have the samemolecular constitution and differ only in the three dimensionalarrangement of their atomic groupings in space. Stereoisomers may bediastereoisomers or enantiomers. It will be recognized that thecompounds described herein may possess asymmetric centers and aretherefore capable of existing in more than one stereoisomeric form. Theinvention thus also relates to compounds in substantially pure isomericform at one or more asymmetric centers e.g., greater than about 90% ee,such as about 95% or 97% ee or greater than 99% ee, as well as mixtures,including racemic mixtures, thereof. Such isomers may be naturallyoccurring or may be prepared by asymmetric synthesis, for example usingchiral intermediates, or by chiral resolution.

The term “substituted” and variants such as “optionally substituted” asused herein, unless otherwise indicated, mean that a substituent may befurther substituted by one or more additional substituents, which may beoptional or otherwise. Examples of additional substituents includeC₁-C₁₀alkyl, C₃-C₁₀alkenyl, C₃-C₁₀alkynyl, aryl, —(C₁-C₄alkyl)aryl,heterocyclyl, heteroaryl, C₃-C₇-cycloalkyl, C₁-C₄-perfluoroalkyl, —OH,—SH, —HN₂, nitrile, C₁-C₁₀-alkoxy, haloC₁₋₄alkyl, hydroxyC₁₋₄alkyl,C₁-C₁₀-alkylthio, —CF₃, halo (F, Cl, Br, I), —NO₂, —CO₂R²³, —NH₂,C₁-C₄alkylamino, C₁-C₄dialkylamino, arylamino, diarylamino,arylC₁₋₄alkylamino, arylC₁₋₄dialkylamino, aryloxy, arylC₁₋₄alkyloxy,formyl, C₁₋₁₀alkylcarbonyl and C₁₋₁₀alkoxycarbonyl, —PO₃H₂, —CO₂H,—CONHSO₂R²¹, —CONHSO₂NHR²⁰, —NHCONHSO₂R²¹, —NHSO₂R²¹, —NHSO₂NHCOR²¹,—SO₂NHR²⁰, —SO₂NHCOR²¹, —SO₂NHCONHR²⁰, —SO₂NHCO₂R²¹, tetrazolyl, —CHO,—CONH₂, —NHCHO, —CO—(C₁-C₆ perfluoroalkyl), —S(O), —(C₁-C₆perfluoroalkyl), wherein R²⁰ is H, C₁-C₅-alkyl, aryl,—(C₁-C₄-alkyl)-aryl, heteroaryl; R²¹ is aryl, C₃-C₇-cycloalkyl,C₁-C₄-perfluoroalkyl, C₁-C₄alkyl, optionally substituted with asubstituent selected from the group consisting of aryl, heteroaryl, —OH,—SH, C₁-C₄-alkyl, C₁-C₄alkoxy, C₁-C₄alkylthio, —CF₃, halo, —NO₂,—CO₂R²³, C₁-C₄-alkylamino, C₁-C₄-dialkylamino, —PO₃H₂, or heteroaryl;and R²² is selected from C₁-C₆-alkyl, C₃-C₆-cycloalkyl, aryl,—(C₁-C₅-alkyl)-aryl, or heteroaryl.

By “vector” is meant a polynucleotide molecule, preferably a DNAmolecule derived, for example, from a plasmid, bacteriophage, yeast orvirus, into which a polynucleotide can be inserted or cloned. A vectorpreferably contains one or more unique restriction sites and can becapable of autonomous replication in a defined host cell including atarget cell or tissue or a progenitor cell or tissue thereof, or beintegrable with the genome of the defined host such that the clonedsequence is reproducible. Accordingly, the vector can be an autonomouslyreplicating vector, i.e., a vector that exists as an extrachromosomalentity, the replication of which is independent of chromosomalreplication, e.g., a linear or closed circular plasmid, anextrachromosomal element, a minichromosome, or an artificial chromosome.The vector can contain any means for assuring self-replication.Alternatively, the vector can be one which, when introduced into thehost cell, is integrated into the genome and replicated together withthe chromosome(s) into which it has been integrated. A vector system cancomprise a single vector or plasmid, two or more vectors or plasmids,which together contain the total DNA to be introduced into the genome ofthe host cell, or a transposon. The choice of the vector will typicallydepend on the compatibility of the vector with the host cell into whichthe vector is to be introduced. In the present case, the vector ispreferably a viral or viral-derived vector, which is operably functionalin animal and preferably mammalian cells. Such vector may be derivedfrom a poxvirus, an adenovirus or yeast. The vector can also include aselection marker such as an antibiotic resistance gene that can be usedfor selection of suitable transformants. Examples of such resistancegenes are known to those of skill in the art and include the nptII genethat confers resistance to the antibiotics kanamycin and G418(Geneticing) and the hph gene which confers resistance to the antibiotichygromycin B.

2. Abbreviations

The following abbreviations are used throughout the application:

d=day

h=hour

s=seconds

i.v.=intravenous

i.p.=intraperitoneal

s.c.=subcutaneous

STZ=streptozotocin

CCI=chronic constriction injury

3. Compositions and Methods for the Treatment or Prophylaxis ofNeuropathic Conditions

The present invention arises from the unexpected discovery that AT₂receptor antagonists are effective in the prevention or attenuation ofthe painful symptoms of neuropathic conditions including primary andsecondary neuropathic conditions. These discoveries are based onpre-clinical data which show that administration of various AT₂ receptorantagonists to rats with a mechanical nerve injury involving a chronicconstriction injury to the sciatic nerve (CCI-rats) or to STZ-diabeticrats causes a dose-dependent attenuation in the development of tactile(mechanical) allodynia, the defining symptom of neuropathic pain.Accordingly, the present invention provides methods for treating orpreventing neuropathic conditions, wherein the methods generallycomprise administering to an individual having, or at risk ofdeveloping, a neuropathic condition, an effective amount of an AT₂receptor antagonist, which is suitably in the form of a pharmaceuticalcomposition. In accordance with the present invention, the AT₂ receptorantagonist can act to prevent or attenuate one or more symptomsassociated with neuropathic conditions including, but not limited to,hyperesthesia, hyperalgesia, allodynia and/or spontaneous burning pain.In some embodiments, the AT₂ receptor antagonist is used to prevent orattenuate one or more symptoms associated with peripheral neuropathicconditions, illustrative examples of which include numbness, weakness,burning pain, shooting pain, and loss of reflexes. The pain may besevere and disabling. In some embodiments, the symptom, which is thesubject of the prevention and/or attenuation, is pain. Accordingly, in arelated aspect, the invention provides methods for preventing and/orattenuating neuropathic pain in an individual, comprising administeringto the individual a pain-preventing or -attenuating effective amount ofan AT₂ receptor antagonist, which is suitably in the form of apharmaceutical composition.

There are many possible causes of neuropathy and it will be understoodthat the present invention contemplates the treatment or prevention ofany neuropathic condition regardless of the cause. In some embodiments,the neuropathic conditions are a result of diseases of the nerves(primary neuropathy) and neuropathy that is caused by systemic disease(secondary neuropathy) such as but not limited to: diabetic neuropathy;Herpes Zoster (shingles)-related neuropathy; uremia-associatedneuropathy; amyloidosis neuropathy; HIV sensory neuropathies; hereditarymotor and sensory neuropathies (HMSN); hereditary sensory neuropathies(HSNs); hereditary sensory and autonomic neuropathies; hereditaryneuropathies with ulcero-mutilation; nitrofurantoin neuropathy;tumaculous neuropathy; neuropathy caused by nutritional deficiency andneuropathy caused by kidney failure. Other causes include repetitiveactivities such as typing or working on an assembly line, medicationsknown to cause peripheral neuropathy such as several antiretroviraldrugs (ddC (zalcitabine) and ddI (didanosine), antibiotics(metronidazole, an antibiotic used for Crohn's disease, isoniazid usedfor tuberculosis), gold compounds (used for rheumatoid arthritis), somechemotherapy drugs (such as vincristine and others) and many others.Chemical compounds are also known to cause peripheral neuropathyincluding alcohol, lead, arsenic, mercury and organophosphatepesticides. Some peripheral neuropathies are associated with infectiousprocesses (such as Guillian-Barre syndrome). In certain embodiments, theneuropathic condition is a peripheral neuropathic condition, which issuitably pain secondary to mechanical nerve injury or painful diabeticneuropathy (PDN) or related condition.

The neuropathic condition may be acute or chronic and, in thisconnection, it will be understood by persons of skill in the art thatthe time course of a neuropathy will vary, based on its underlyingcause. With trauma, the onset of symptoms may be acute, or sudden;however, the most severe symptoms may develop over time and persist foryears. Inflammatory and some metabolic neuropathies have a subacutecourse extending over days to weeks. A chronic course over weeks tomonths usually indicates a toxic or metabolic neuropathy. A chronic,slowly progressive neuropathy over many years such as occurs withpainful diabetic neuropathy or with most hereditary neuropathies or witha condition termed chronic inflammatory demyelinatingpolyradiculoneuropathy (CIDP). Neuropathic conditions with symptoms thatrelapse and remit include the Guillian-Barre syndrome.

The AT₂ receptor antagonist includes and encompasses any active compoundthat binds to the AT₂ receptor subtype and that suitably inhibits theeffect of angiotensin II signaling through this receptor, includingpharmaceutical compatible salts of the active compound. This categoryincludes compounds having differing structural features. For example, insome embodiments, the AT₂ receptor antagonist is selected from thecompounds listed in U.S. Pat. No. 5,798,415 and especially in thecompound claims of this patent. In illustrative examples of this type,the AT₂ receptor antagonist is selected from compounds having theformula (Ia):

or their pharmaceutically compatible salts,

wherein:

-   -   Q is naphthyl, a 5 to 7 member heterocycle having from 1 to 3        atoms independently selected from nitrogen, oxygen and sulfur,        or an 8 to 11 member heterobicycle having from 1 to 4 atoms        selected from nitrogen, oxygen and sulfur, said heterocycle or        heterobicycle being saturated, partially saturated or        unsaturated and said naphthyl, heterocycle or heterobicycle        optionally substituted with 1 to 4 W′ substituents;    -   each W¹ substituent is independently selected from halo,        hydroxy, nitro, cyano, C₁ to C₈ alkyl, C₃ to C₇ cycloalkyl, C₁        to C₇ alkoxy, amino, C₁ to C₇ alkylamino, di(C₁ to C₇        alkyl)amino, C₁ to C₇ alkylthio, C₁ to C₇ alkylsulfinyl, C₁ to        C₇ alkylsulfonyl, —CONRR, —COOR and phenyl, said alkyl,        cycloalkyl, alkoxy, alkylamino, dialkylamino, alkylthio,        alkylsulfinyl and alkylsulfonyl optionally substituted with 1 or        more W² substituents, and said phenyl optionally substituted        with 1 or more W³ substituents;    -   each R is independently hydrogen or C₁ to C₈ alkyl, said alkyl        optionally substituted with 1 or more W² substituents;    -   each W² substituent is independently selected from halo,        hydroxy, oxo, C₃ to C₇ cycloalkyl, C₁ to C₇ alkoxy, acyloxy,        phenyl and 5 to 7 member heterocycle having 1 to 3 atoms        selected from nitrogen, oxygen and sulfur, said phenyl and        heterocycle optionally substituted with 1 or more W³        substituents;    -   each W³ substituent is independently selected from halo,        hydroxy, nitro, C₃ to C₇ cycloalkyl, C₁ to C₇ alkoxy, amino, C₁        to C₇ alkylamino, di(C₁ to C₇ alkyl)amino, C₁ to C₇ alkylthio,        C₁ to C₇ alkylsulfinyl and C₁ to C₇ alkylsulfonyl;    -   R¹ and R², when taken separately, are each independently        selected from hydrogen, hydroxy, C₁ to C₁₀ alkyl, C₁ to C₇        alkylthio, C₁ to C₇ alkylsulfinyl, C₁ to C₇ alkylsulfonyl,        phenyl and 5 to 7 member heterocycle or 8 to 11 member        heterobicycle, having 1 to 3 atoms selected from nitrogen,        oxygen and sulfur, said alkyl, alkylthio, alkylsulfinyl and        alkylsulfonyl optionally substituted with 1 or more W⁴        substituents, said phenyl and said heterocycle and heterobicycle        optionally substituted with 1 to 5 W³ substituents, wherein the        W³ substituents are as defined above, and said heterocycle being        saturated, partially saturated or unsaturated, provided that R¹        and R² are not both hydroxy;

R¹ and R², when taken together with the carbon atom to which they areattached, form a C₃ to C₇ carbocyclic, C₇ to C₁₁ carbobicyclic, 3 to 7member heterocyclic group having from 1 to 3 atoms independentlyselected from nitrogen, oxygen and sulfur, or a 7 to 11 memberheterobicyclic group having from 1 to 4 atoms independently selectedfrom nitrogen, oxygen and sulfur, said carbocyclic, carbobicyclic,heterocyclic or heterobicyclic group being saturated, partiallysaturated or unsaturated and optionally substituted with 1 or more W⁵substituents;

-   -   each W⁴ substituent is independently selected from halo, C₃ to        C₈ cycloalkyl, phenyl and 5 to 7 member heterocycle having 1 to        3 atoms selected from nitrogen, oxygen and sulfur, said phenyl        and heterocycle optionally substituted with 1 or more        substituents independently selected from halo, hydroxy, nitro,        C₁ to C₁₀ alkyl, C₃ to C₇ cycloalkyl, C₁ to C₇ alkoxy, amino, C₁        to C₇ alkylamino and di(C₁ to C₇ alkyl)amino;    -   each W⁵ substituent is independently selected from halo,        hydroxy, nitro, cyano, oxo, C₁ to C₈ alkyl, C₃ to C₇ cycloalkyl,        C₁ to C₇ alkoxy, amino, C₁ to C₇ alkylamino, di(C₁ to C₇        alkyl)amino, C₁ to C₇ alkylthio, C₁ to C₇ alkylsulfinyl, C₁ to        C₇ alkylsulfonyl, —CONRR, —COOR and phenyl, said alkyl,        cycloalkyl, alkoxy, alkylamino, dialkylamino, alkylthio,        alkylsulfinyl and alkylsulfonyl groups optionally substituted        with 1 or more W² substituents, and said phenyl optionally        substituted with 1 or more W³ substituents, wherein the W³        substituents are as defined above;    -   R³ is —(CH₂)_(n) COR⁴, tetrazolyl, C₁ to C₅ alkyltetrazolyl,        triazolyl, C₁ to C₅ alkyltriazolyl, —(CH₂)_(n)CH₂OH, —SO₂R⁴,        —SO₂NR⁵R⁶ or —NHSO₂R⁷;    -   R⁴ is hydrogen, hydroxy, —NHSO₂R⁷, C₁ to C₁₀ alkoxy, C₁ to C₇        alkylthio, —NR⁵R⁶, —NHSO₂R⁷ or —OY, said alkoxy and alkylthio        groups optionally substituted with 1 or more W⁶ substituents;    -   n is an integer from 0 to 5;    -   Y is a pharmaceutically acceptable cation or a group        hydrolyzable under physiological conditions;    -   R⁵ and R⁶, when taken separately, are each independently        hydrogen, hydroxy, cyano, C₁ to C₁₀ alkyl, C₁ to C₈ alkoxy,        —COR, —CONRR, —COOR, phenoxy, —CO(C₆H₅) or 5 to 6 member        heterocycle having 1 to 4 atoms selected from nitrogen, oxygen        and sulfur, wherein R is as defined above, said alkyl optionally        substituted with 1 or more W³ substituents, wherein the W³        substituents are as defined above, said —CO(C₆H₅) optionally        substituted with 1 to 3 W⁶ substituents and said heterocycle        optionally substituted with 1 or more W⁵ substituents, wherein        the W⁵ substituents are as defined above;    -   R⁵ and R⁶, when taken together with the nitrogen atom to which        they are attached, form a 3 to 7 member ring having 1 to 3        nitrogen atoms and from 0 to 3 atoms selected from oxygen and        sulfur, said ring being saturated, partially saturated or        unsaturated and optionally substituted with 1 or more W¹        substituents, wherein the W¹ substituents are as defined above;    -   R⁷ is C₁ to C₁₀ alkyl or phenyl, said alkyl optionally        substituted with 1 or more W⁶ substituents, and said phenyl        optionally substituted with 1 or more W³ substituents, wherein        the W³ substituents are as defined above;    -   X is an azacyclic group of the formula:

-   -   L¹, L², L³, L⁴ and L⁵, when taken separately, are independently        hydrogen, halo, nitro, C₁ to C₉ alkyl, C₃ to C₇ cycloalkyl,        polyfluoro-C₁ to C₄ alkyl, aryl, heteroaryl, tetrazol-5-yl,        —COR^(S), —CO₂R⁸, —CONHSO₂R⁹, —CONR¹⁰R¹⁰, —CONH(tetrazol-5-yl),        —OR⁹, —COCNR⁹R¹¹, —NR⁸R⁹, —NHCOR⁹, —NHCO₂R⁹, —NHCONR⁸R⁹,        —NHSO₂R⁹, —NHSO₂NR⁹R¹¹, —NHSO₂-polyfluorophenyl, —SR⁹, —SOR⁹,        —SO₂R⁹, —SO²NHCN, —SO²NR¹¹R¹², —SO₂NHCOR⁹, —SO₂NH-heteroaryl,        —PO(OR⁸)₂ or —PO(OR⁸)R¹¹, said alkyl, cycloalkyl, aryl and        heteroaryl groups optionally substituted with 1 or more        substituents selected from hydroxy, halo, C₁ to C₄        perfluoroalkyl, C₁ to C₄ alkoxy, aryl, heteroaryl, guanidino,        morpholino, tetrazol-5-yl, —COR⁸, —CO₂R⁸, —CONHSO₂R⁹, —CONR⁸R⁸,        —O—COR⁸, —NR⁸R⁸, —NR¹²COOR⁹, —N(C₁ to C₆ alkyl)piperazine, —SR⁹,        —SOR⁹, —SO₂R⁹, —SO₂NR⁸CN, —SO₂NR⁸COR⁹, —SO₂NR⁸-heteroaryl,        —PO(OR⁸)₂ and —PO(OR⁸)R¹¹;    -   L¹ and L², L² and L³, L³ and L⁴ or L⁴ and L⁵, when taken        together with the azacyclic group to which they are attached,        form a fused 8 to 11 member azabicyclic system having 1 to 5        nitrogen atoms and 0 to 3 atoms selected from oxygen and sulfur,        said azabicyclic system optionally substituted with 1 to 3 W⁶        substituents;    -   each W⁶ substituent is independently halo, nitro, cyano, C₁ to        C₆ alkyl, C₃ to C₇ cycloalkyl, polyfluoro-C₁ to C₄ alkyl, aryl,        heteroaryl, tetrazol-5-yl, —COR^(S), —CO₂R⁸, —CONR⁸SO₂R⁹,        —CONR⁹R¹⁰, —CONR⁸(tetrazol-5-yl), —OR⁹, —OCONR⁹R¹¹, —NR⁸R⁹,        —NR⁸COR⁹, —NR⁸COR⁹—NR⁸CONR⁸R⁹, —NR⁸SO₂R⁹, —NR⁸SO₂NR₉R¹¹,        —NR⁸SO₂-polyfluorophenyl, —SR⁹, —SOR⁹, —SO₂R⁹, —SO₂NR₈CN,        —SO₂NR⁹R⁴², —SO NR⁸COR⁹, —SO₂NR⁸-heteroaryl, —PO(OR⁸)₂ or        —PO(OR⁸)R¹¹, said alkyl, cycloalkyl, aryl and heteroaryl groups        optionally substituted with 1 or more substituents selected from        hydroxy, halo, C₁ to C₄ perfluoroalkyl, C₁ to C₄ alkoxy, aryl,        heteroaryl, guanidino, morpholino, tetrazol-5-yl, —COR⁸, —CO₂R⁸,        —CONR⁸SO₂R⁹, —CONR⁸, R⁹, —O—COR⁸, —NR⁸, R⁹, —NR¹²COOR⁹, —N(C₁ to        C₆ alkyl)piperazine, —SR⁹, —SOR⁹, —SO₂R⁹, —SO₂ NR⁸CN,        —SO₂NR⁸COR⁹, —SO₂NR⁸-heteroaryl, —PO(OR⁸)₂ and —PO(OR⁸)R¹³;    -   each R⁸ is independently hydrogen, C₁ to C₆ alkyl, C₃ to C₇        cycloalkyl, aryl, heteroaryl or aryl(C₁ to C₆)alkyl;    -   each R⁹ is independently hydrogen, C₁ to C₁₀ alkyl, C₃ to C₇        cycloalkyl, aryl, heteroaryl or polyfluoro(C₁ to C₄)alkyl, said        alkyl and cycloalkyl optionally substituted with 1 or more        substituents selected from halo, hydroxy, nitro, C₁ to C₄        alkoxy, C₁ to C₄ alkylthio, —CO₂R¹², amino, C₁ to C₄ alkylamino,        di(C₁ to C₄)alkylamino, aryl, heteroaryl, —SH, —PO₃H₂,        —P(O)(OH)(O—C₁ to C₄ alkyl), P(O)(OR⁸)(R¹¹) or P(O)(OR¹⁴)(R¹⁵);    -   each R¹¹ is independently hydrogen, C₁ to C₅ alkyl, aryl or        —CH₂-aryl;    -   each R₁₁ is independently hydrogen, C₁ to C₅ alkyl, C₃ to C₇        cycloalkyl, aryl or —C₁₋₁₂-aryl;    -   each R¹² is hydrogen or C₁ to C₄ alkyl;    -   each R¹³ is independently hydrogen, C₁ to C₅ alkyl, C₁ to C₄        alkenyl, C₁ to C₄ alkoxy(C₁ to C₄)alkyl or benzyl, said benzyl        optionally substituted with 1 or more substituents independently        selected from hydroxy, amino, nitro and methoxy;    -   R¹⁴ and R¹⁵ are taken together and form a 5 to 7 member ring        having 1 to 3 atoms independently selected from nitrogen, oxygen        and sulfur;    -   M¹ and M² are taken together and are —(CH₂)_(m); and    -   m is an integer from 3 to 7.

Preferred compounds are those of formula (I) wherein:

-   -   X is

-   -   L¹, L² and L⁴ are as defined above;    -   Q is thiophene, pyridine, pyrimidine, naphthyl, benzofuran or        any of the foregoing substituted with 1 or 2 W¹ substituents; R¹        and R² are taken together as defined above;    -   R³ is —(CH₂)_(n) COR⁴; n is 0 or 1; R⁴ is hydrogen, hydroxy or        —OY;    -   Y is a pharmaceutically acceptable cation or a group        hydrolyzable under physiological conditions; and    -   each W¹ is independently halo, hydroxy, C₁ to C₈ alkyl, C₃ to C₇        cycloalkyl, C₁ to C₇ alkoxy, amino, C₁ to C₇ alkylamino, di(C₁        to C₇ alkyl)amino, —CONRR or —COOR, wherein R is as defined        above.

Particularly preferred are those compounds wherein X, Q, R³, R⁴, n and Yare as defined immediately above and wherein:

-   -   R¹ and R² are taken together and form a C₅ to C₆ carbocyclic, C₈        to C₁₀ carbobicyclic or 5 to 7 member heterocyclic group having        1 or 2 atoms independently selected from nitrogen, oxygen and        sulfur, said carbocyclic, carbobicyclic or heterocyclic group        being saturated, partially saturated or unsaturated;    -   L¹ and L², when taken separately, are each independently        hydrogen, halo, C₁ to C₆ alkyl, C₃ to C₇ cycloalkyl,        polyfluoro-C₁ to C₄ alkyl or —CO₂R⁸;    -   L¹ and L², when taken together with the azacyclic group to which        they are attached, form a fused 8 to 10 member azabicyclic        system having 2 to 4 nitrogen atoms, said azabicyclic system        optionally substituted with 1 to 3 W⁶ substituents;    -   L⁴ is C₁ to C₄ alkyl, C₃ to C₅ cycloalkyl or C₁ to C₃ alkoxy;    -   R⁸ is hydrogen, C₁ to C₆ alkyl or C₃ to C₇ cycloalkyl; and each        W⁶ is independently halo, C₁ to C₆ alkyl, C₃ to C₇ cycloalkyl,        polyfluoro-C₁ to C₄ alkyl, —CO₂R⁸, amino, C₁ to C₆ alkylamino,        di(C₁ to C₆)alkylamino, acylamino or diacylamino.

Among the particularly preferred compounds defined above are thosehaving the structure:

wherein:

-   -   L4 is C₁ to C₄ alkyl or C₃ to C₅ cycloalkyl;    -   each W⁶ is independently C₁ to C₆ alkyl, amino, C₁ to C₆        alkylamino, di(C₁ to C₆)alkylamino, acylamino or diacylamino;        and    -   R¹ and R² are taken together and form cyclopentane, cyclohexane,        cyclopentane, tetrahydropyran or indan, for example:

-   1-[5-(2-ethyl-5,7-dimethylimidazo[4.5-b]pyridin-3-ylmethyl)thiophen-2-yl]-cyclopent-3-ene    carboxylic acid;

-   1-[5-(5,7-dimethyl-2-propylimidazo[4.5-b]pyridin-3-ylmethyl)thiophen-2-yl]cyclopent-3-ene    carboxylic acid;

-   1-[5-(2-cyclopropyl-5,7-dimethylimidazo[4.5-b]pyridin-3-ylmethyl)thiophen-2-yl]cyclopent-3-ene    carboxylic acid;

-   1->5-(2-cyclopropyl-5,7-dimethylimidazo[4.5-b]pyridin-3-ylmethyl)thiophen-2-yl]cyclopentane    carboxylic acid;

-   4-[5-(2-ethyl-5,7-dimethylimidazo[4.5-b]pyridin-3-ylmethyl)thiophen-2-yl]tetrahydropyran-4-carboxylic    acid;

-   2-[5-(2-ethyl-5,7-dimethylimidazo[4.5-b]pyridin-3-ylmethyl)thiophen-2-yl]indan-2-carboxylic    acid;

-   2-[5-(2-cyclopropyl-5,7-dimethylimidazo[4,5-b]pyridin-3-ylmethyl)thiophen-2-yl]indan-2-carboxylic    acid;

-   1-[5-(2-ethyl-5,7-dimethylimidazo[4,5-b]pyridin-3-ylmethyl)thiophen-2-yl]cyclohexane    carboxylic acid; and

-   1-[5-(2-cyclopropyl-5,7-dimethylimidazo[4.5-b]pyridin-3-ylmethyl)thiophen-2-yl]cyclohexane    carboxylic acid.

Also among the particularly preferred compounds defined above are thosehaving the structure

wherein:

-   -   Q is

-   -   L⁴ is C₁ to C₄ alkyl or C₃ to C₅ cycloalkyl; and    -   R¹ and R² are taken together and are —CH₂CH₂CH₂C₁₋₁₂— or        —CH₂CH═CHCH₂—, for example:

-   1-[5-(2-ethyl-5,7-dimethylimidaz[4.5-b]pyridin-3-ylmethyl)pyridin-2-yl]cyclopentane    carboxylic acid;

-   1-[5-(2-cyclopropyl-5,7-dimethylimidazo[4.5-b]pyridin-3-ylmethyl)pyridin-2-yl]cyclopentane    carboxylic acid;

-   1-[2-(2-ethyl-5,7-dimethylimidazo[4.5-b]pyridin-3-ylmethyl)pyrimidin-5-yl]cyclopent-3-ene    carboxylic acid;

-   1-[2-(2-cyclopropyl-5,7-dimethylimidazo[4.5-b]pyridin-3-ylmethyl)pyrimidin-5-yl]cyclopent-3-ene    carboxylic acid;

-   1-[6-(2-ethyl-5,7-dimethylimidazo[4.5-b]pyridin-3-ylmethyl)naphthalen-2-yl]cyclopent-3-ene    carboxylic acid; and

-   1-[3-bromo-5-(2-ethyl-5,7-dimethylimidazo[4.5-b]pyridin-3-ylmethyl)benzofuran-2-yl]cyclopentane    carboxylic acid.

Also among the particularly preferred compounds defined above are thosehaving the structure

wherein:

-   -   Q is

-   -   L¹ and L² are taken separately and are each independently halo,        C₁ to C₆ alkyl or —CO₂H;    -   L⁴ is C₁ to C₄ alkyl; and    -   R¹ and R² are taken together and are —CH₂CH₂CH₂CH₂— or        —CH₂CH═CHCH₂—, for example:

-   2-butyl-3-[5-(1-carboxycyclopent-3-enyl)thiophen-2-ylmethyl]-5-chloro-3H-imidazole-4-carboxylic    acid;

-   3-[5-(1-carboxycyclopent-3-enyl)thiophen-2-ylmethyl]-5-ethyl-2-propyl-3H-imidazole-4-carboxylic    acid; and

-   3-[5-(1-carboxycyclopent-3-enyl)thiophen-2-ylmethyl]-5-chloro-2-propyl-3H-imidazole-4-carboxylic    acid.

Also among the particularly preferred compounds defined above are thosehaving the structure

wherein:

-   -   Q is

-   -   L⁴ is C₁ to C₄ alkyl; and    -   R¹ and R² are taken together and are —CH₂CH₂CH₂CH₂— or        —CH₂CH═CHCH₂—, for example:

-   1-[5-(2-butyl-5-methyl-4-oxo-4H-quinazolin-3-ylmethyl)pyridin-2-yl]cyclopentane    carboxylic acid; and

-   1-[5-(2-butyl-5-methyl-4-oxo-4H-quinazolin-3-ylmethyl)thiophen-2-yl]cyclopent-3-ene    carboxylic acid.

Also among the particularly preferred compounds defined above are thosehaving the structure

wherein:

-   -   L¹ and L² are taken separately and are each independently halo,        C₁ to C₆ alkyl, polyfluoro-C₁ to C₆ alkyl or —CO₂H;    -   L⁴ is C₁ to C₄ alkyl; and    -   R¹ and R₂ are taken together and are —CH₂CH₂CH₂CH₂— or        —CH₂CH═CHCH₂—, for example:

-   2,5-dibutyl-4-[5-(1-carboxycyclopent-3-enyl)thiophen-2-ylmethyl]-2H-pyrazole-3-carboxylic    acid;

-   5-butyl-4-[5-(1-carboxycyclopent-3-enyl)thiophen-2-ylmethyl]-2-trifluoromethyl-2H-pyrazole-3-carboxylic    acid; and

-   5-butyl-4-[5-(1-carboxycyclopent-3-enyl)thiophen-2-ylmethyl]-2-propyl-2    H-pyrazole-3-carboxylic acid.

Other preferred compounds include compounds in the same general classas:

-   1-[5-(2-cyclopropyl-5,7-dimethylimidazo[4.5-b]pyridin-3-ylmethyl)thiophen-2-yl]cyclopenten-3-ene    carboxylic acid benzenesulfonamide;-   1-[5-(2-cyclopropyl-5,7-dimethylimidazo[4.5-b]pyridin-3-ylmethyl)thiophen-2-yl]cyclopenten-3-ene    carboxylic acid p-toluenesulfonamide;-   1-[5-(2-cyclopropyl-5,7-dimethylimidazo[4.5-b]pyridin-3-ylmethyl)thiophen-2-yl]cyclopenten-3-ene    carboxylic acid methanesulfonamide; and-   1-[5-(2-cyclopropyl-5,7-dimethylimidazo[4.5-b]pyridin-3-ylmethyl)thiophen-2-yl]cyclopenten-3-ene    carboxylic acid trifluoromethanesulfonamide.

Various intermediates also fall within the scope of the presentinvention, including:

-   1-thiophen-2-yl-cyclopent-3-ene carboxylic acid ethyl ester;-   1-(5-formylthiophen-2-yl)cyclopent-3-ene carboxylic acid ethyl    ester;-   1-(5-chloromethylthiophen-2-yl)cyclopent-3-ene carboxylic acid ethyl    ester; and-   1-[5-(2-ethyl-5,7-dimethylimidazo>4,5-b!pyridin-3-ylmethyl)thiophen-2-yl!cyclopent-3-ene    carboxylic acid ethyl ester.

In other embodiments, the AT₂ receptor antagonist is selected from thedisubstituted 6-aminoquinazolinone compounds listed in U.S. Pat. No.5,385,894 and especially in the compound claims of this patent.Representative examples of such compounds are represented by the formula(IIa):

or a pharmaceutically compatible salt thereof, wherein:

R¹ is

-   -   (a) CO₂R²,    -   (b) tetrazol-5-yl,    -   (c) NHSO₂CF₃,    -   (d) SO₂NHCOR³, or    -   (e) SO₂NH-heteroaryl;

R² is

-   -   (a) hydrogen, or    -   (b) C₁-C₆ alkyl;

R³ is

-   -   (a) C₁-C₆ alkyl,    -   (b) C₃-C₇ cycloalkyl,    -   (c) phenyl,    -   (d) substituted phenyl in which the substituent is F, Cl, Br,        C₁-C₄ alkoxy, perfluoro C₁-C₄ alkyl, di-(C₁-C₄-alkyl)amino, or        CO₂R²,    -   (e) substituted C₁-C₈ alkyl in which the substituent is C₃-C₇        cycloalkyl, C₁-C₄ alkoxy, hydroxy, di-(C₁-C₄ alkyl)amino, CO₂R₂,        morpholinyl, C₁-C₄ alkylpiperazinyl, CF₃, thio, C₁-C₄        alkylsulfinyl, C₁-C₄ alkylsulfonyl, heteroaryl, NH₂, or aryl, or    -   (f) heteroaryl;

R⁴ is

-   -   (a) C₁-C₆ alkyl,    -   (b) substituted C₁-C₆ alkyl in which the substituent is C₃-C₇        cycloalkyl, alkoxy, hydroxy, alkyl)amino, CO₂R₂, morpholinyl,        C₁-C₄ alkylpiperazinyl, CF₃, C₁-C₄ alkylthio, C₁-C₄        alkylsulfinyl, C₁-C₄ alkylsulfonyl, —CHO, O(C₂-C₃ alkyl-O—)_(n)        C₁-C₃ alkyl where n=1-5, or NHCO₂(C₁-C₆-alkyl).    -   (c) C₂-C₆ alkenyl,    -   (d) phenyl C₁-C₆ alkyl,    -   (e) substituted phenyl C₁-C₆ alkyl, in which the substituent on        the phenyl group is hydroxy, C₁-C₄ alkoxy, F, Cl, I, Br, NO₂,        cyano, CO₂R², di(C₁-C₄ alkyl)amino, —Obenzyl, CF₃,        phenyl-C₁-C₄-alkoxy, C₁-C₄ alkylthio, C₁-C₄-alkylsulfinyl,        —OPO(O-benzyl)₂, or C₁-C₄ alkylsulfonyl, amino, P(O)(OH)₂, C₁-C₄        alkyl, —OPO(O—C₁-C₆ alkyl)₂, OPO(OH)₂, OCO(CH₂)₂COOH, OSO₃H, or        O(C₂-C₃ alkyl-O—)_(n) C₁-C₃ alkyl,    -   (f) heteroaryl C₁-C₆ alkyl, or    -   (g) substituted heteroaryl C₁-C₆ alkyl, in which the substituent        on the heteroaryl group is F, Cl, NO₂, CO₂R², or di-(C₁-C₄        alkyl)amino;

R⁵ is

-   -   (a) CO₂R⁷,    -   (b) CONR⁸R⁹,    -   (c) COR¹⁰,    -   (d) SO²NR⁸R⁹, or    -   (e) SO₂R¹⁰;

R⁶ is

-   -   (a) C₁-C₆ alkyl,    -   (b) substituted C₁-C₆ alkyl in which the substituent is C₃-C₇        cycloalkyl, benzyl or C₁-C₄-alkoxy,    -   (c) cyclopropyl;

R⁷ is

-   -   (a) C₁-C₆ alkyl,    -   (b) substituted C₁-C₆ alkyl in which the substituent is C₁-C₄        alkoxy, hydroxy, di(C₁-C₄ alkyl)amino, CO₂R², morpholinyl, C₁-C₄        alkylpiperazinyl, C₁-C₄ alkylsulfinyl, C₁-C₄ alkylsulfonyl, or        O(C₂-C₃ alkyl-O—)_(n) C₁-C₃ alkyl,    -   (c) phenyl C₁-C₆ alkyl,    -   (d) substituted phenyl C₁-C₆ alkyl, in which the substituent on        the phenyl group is hydroxy, C₁-C₄ alkoxy, F, Cl, NO₂, cyano,        CO₂R², di(C₁-C₄ alkyl)amino, CF₃, phenyl C₁-C₄ alkoxy, C₁-C₄        alkylthio, C₁-C₄ alkylsulfinyl, C₁-C₄ alkylsulfonyl, or O(C₂-C₃        alkyl-O—)_(n) C₁-C₃ alkyl,    -   (e) heteroaryl C₁-C₆ alkyl, or    -   (f) substituted heteroaryl C.sub.1-C.sub.6 alkyl, in which the        substituent on the heteroaryl group is F, Cl, NO₂, CO₂R², or        di-(C₁-C₄ alkyl)amino;

R⁸ is

-   -   (a) hydrogen, or    -   (b) C₁-C₆ alkyl;

R⁹ is

-   -   (a) C₁-C₆ alkyl, or    -   (b) substituted C₁-C₆ alkyl in which the substituent is C₁-C₄        alkoxy, hydroxy, di-(C₁-C₄ alkyl)amino, CO₂R², morpholinyl,        C₁-C₄ alkylpiperazinyl, C₁-C₄ alkylsulfinyl or C₁-C₄        alkylsulfonyl,    -   (c) perfluoro C₁-C₆ alkyl,    -   (d) phenyl,    -   (e) heteroaryl, or

R⁸ and R⁹ taken together are morpholino,

R¹⁰ is

-   -   (a) phenyl,

(b) substituted phenyl in which the substituent is F, Cl, Br, I,C₁-C₄-alkoxy, C₁-C₄ alkyl, NO₂, cyano, OC₆H₅, CO₂R₂, di(C₁-C₄alkylamino), CF₃, C₁-C₄ alkylthio, C₁-C₄ alkylsulfinyl, C₁-C₄alkylsulfonyl, —OPO(OC₁-C₆-alkyl)₂, OPO(OH)₂, OPO(O-benzyl)₂,OCO(CH₂)₂COOH, OSO₂OH, —PO(OC₁-C₆-alkyl)₂, —PO(OH)₂, OBn, or O—(C₂-C₃alkyl-O)_(n) C₁-C₃ alkyl,

-   -   (c) phenyl C1-C6 alkyl,    -   (d) heteroaryl,    -   (e) C1-C6 alkyl,    -   (f) substituted C₁-C₆ alkyl in which the substituent is C₃-C₇        cycloalkyl, C₁-C₄ alkoxy, hydroxy, di-(C₁-C₄ alkyl)amino, CO₂R²,        morpholinyl, C₄ alkylpiperazinyl, CF₃, thio, C₁-C₄        alkylsulfinyl, C₁-C₄ alkylsulfonyl, imidazolyl, —N(COC1-C6        alkyl)piperazinyl, or N-aryl-piperazinyl    -   (g) substituted phenyl C₁-C₆ alkyl, in which the substituent on        the phenyl group is hydroxy, C₁-C₄ alkoxy, F, Cl, NO₂, cyano,        CO₂R², di(C₁-C₄ alkyl)amino, CF₃, phenyl C₁-C₄ alkoxy, thio,        C₁-C₄ alkylsulfinyl, or C₁-C₄-alkylsulfonyl, or    -   (h) C₃-C₇ cycloalkyl.

R¹¹ is

-   -   (a) hydrogen,    -   (b) F, Cl, Br or I    -   (c) C₁-C₄ alkyl,    -   (d) C₁-C₄ alkoxy,

R¹² is

-   -   (a) hydrogen,    -   (b) C₁-C₅ alkyl,    -   (c) phenyl,    -   (d) substituted phenyl in which the substituent is C₁-C₄ alkoxy,        F, Cl, CO₂R², di(C₁-C₄ alkyl)amino, thio, C₁-C₄ alkylsulfinyl,        C₁-C₄ alkylsulfonyl.

In some of the above embodiments, the term heteroaryl means anunsubstituted, monosubstituted or disubstituted five or six memberedaromatic ring which contains 1 to 3 heteroatoms selected from O, S, or Nand the substituents are selected from the group consisting of C₁-C₄alkyl, F, Cl, CO₂R², or di-(C₁-C₄ alkyl)amino.

The abbreviations defined in the table below are used in the specificembodiments which are illustrated in tabular form:

Table of Abbreviations Me methyl iPn isopentyl Et ethyl Hex n-hexyl Prn-propyl cHex cyclohexyl iPr isopropyl Boc butyloxycarbonyl cPrcyclopropyl Ph phenyl Bu n-butyl Bn benzyl iBu isobutyl Bz benzoyl tButertbutyl TET tetrazol-5-yl Pn n-pentyl PIP Piperazinyl

In a first specific embodiment of the compounds according to formula(IIa), R⁵ is CO₂R⁷. One class of this embodiment is represented by thecompounds of the formula (IIa) wherein:

R¹ is tetrazol-5-yl or SO₂NHCOR³ or NHSO₂CF₃

R³ is

-   -   a) phenyl,    -   b) substituted phenyl in which the substituent is F, Cl, Br, I        or C₁-C₄ alkoxy,    -   c) C₁-C₈ alkyl substituted with di-(C₁-C₄-alkyl)amino or NH₂, or    -   d) C₃-C₇-cycloalkyl;

R⁴ is

-   -   a) C₂-C₆ alkyl,    -   b) substituted C₂-C₆ alkyl in which the substituent is: CHO,        CO₂C₁-C₄ alkyl, CO₂H, OC₁-C₄ alkyl, cyclohexyl, phenyl,        NHCO₂tBu,    -   c) benzyl,    -   d) substituted benzyl in which the substituent on the phenyl        group is: F, Cl, Br, I, OH, OPO(OC₁-C₄ alkyl)₂, OPO(Obenzyl)₂,        OPO(OH)₂, —PO(OC₁-C₄ alkyl)₂, —PO(Obenzyl)₂, OPO(OH)₂, NO₂, NH₂,        N(C_(t)—C₄ alkyl)₂, Obenzyl,    -   e) CH₂-heteroaryl or    -   f) C₃-C₆ alkenyl;

R⁶ is

-   -   a) C₁-C₆ alkyl,    -   b) substituted C₁-C₆ alkyl in which the substituent is: -benzyl,        —C₁-C₃ alkyl, or —OC₁-C₄ alkyl, or    -   c) cyclopropyl;

R⁷ is

-   -   a) C₁-C₆ alkyl,    -   b) benzyl,    -   c) C₂-C₄ alkyl-O—C₁-C₄ alkyl or    -   d) phenyl;

R¹¹ and R¹² are hydrogen,

Illustrating the first class of this embodiment are the followingcompounds (with their Compound Number designation) of the formula (IIa):

R⁶ R¹ R⁷ R⁴ Pr TET iBu Et Bu TET iBu Bn Bu TET tBu Me Pr TET iBu Bu PrTET Et Me Pr TET iPr Me Pr TET Me Me Pr TET Bu Me Pr TET iBu Pr Pr TETiBu Allyl Pr TET iBu Pn Pr TET iBu Pn Pr TET iBu (CH₂)₃Ph Pr TET Me BnPr TET iBu Bn Pr TET Pr Bn Pr TET Bu Bn Pr TET Bn Bz Pr TET Hex Bn PrTET tBu Bn Pr TET (CH₂)₂OMe Bn Pr TET Pr CH₂cHex Pr TET Bu Bu Pr TET(CH₂)₂OEt (CH₂)₂OMe Et TET iBu Me Et TET iBu Bn iBu TET iBu Me iBu TETiBu Bn Me TET iBu Bn Me TET iBu Me Pr SO₂NHCOPh iBu Me Pr TET Et Bn PrTET Ph CH₂-2-Pyr Et TET tBu Bn Et TET Bn Bn Bu SO₂NHBz iBu Bn Pr SO₂NHBzBu Bn Pr SO₂NHCOcPr iBu Bn Pr SO₂NHCOcPr iBu Me Pr TET Pr CH₂-4-Pyr PrTET (CH₂)₂OMe Me Pr TET Pr CH₂-3-Pyr Pr TET Pr CH₂-2-Pyr Pr TET(CH₂)₂OMe CH₂-4-Pyr CH₂OMe TET iBu Me CH₂OMe TET Pr CH₂-2-Pyr Pr SO₂NHBzBn Pn Pr TET Et CH₂-2-Pyr Pr TET Pr Bn-4-NO₂ Pr TET Pr Bn-4-NH₂ Pr TETPr Bn-4-NMe₂ H TET iBu Me

In a second specific embodiment of the compounds according to formula(IIa), R⁵ is CONR⁸R⁹. One class of this embodiment is represented by thecompounds of the formula (IIa) wherein:

R¹ is tetrazol-5-yl or SO₂NHCOR³ or NHSO₂CF₃,

R³ is

-   -   a) phenyl,    -   b) substituted phenyl in which the substituent is F, Cl, Br, I        or C₁-C₄ alkoxy,    -   c) C₁-C₈ alkyl substituted with di-(C₁-C₄-alkyl)amino or NH₂, or    -   d) C₃-C₇-cycloalkyl;

R⁴ is

-   -   a) C₂-C₆ alkyl,    -   b) substituted C₂-C₆ alkyl in which the substituent is: CHO,        CO₂C₁-C₄ alkyl, CO₂H, OC₁-C₄ alkyl, cyclohexyl, phenyl, or        NHCO₂Bu,    -   c) benzyl,    -   d) substituted benzyl in which the substituent on the phenyl        group is: F, Cl, Br, I, OH, OPO(OC₁-C₄ alkyl)₂, OPO(Obenzyl)₂,        OPO(OH)₂, —PO(OC₁-C₄alkyl)₂, —PO(Obenzyl)₂, —OPO(OH)₂, NO₂,        N(C₁-C₄ alkyl)₂, or Obenzyl,    -   e) CH₂-heteroaryl, or    -   f) C₃-C₆ alkenyl;

R⁶ is

-   -   a) C₁-C₆ alkyl,    -   b) substituted C₁-C₆ alkyl in which the substituent is: -benzyl,        —C₁-C₃ alkyl, or —OC₁-C₄ alkyl, or    -   c) cyclopropyl;

R⁸ is

-   -   a) C₁-C₆ alkyl or    -   b) hydrogen;

R⁹ is

-   -   a) C₁-C₆ alkyl, or    -   b) when taken with R⁸ and the nitrogen atom to which they are        attached from a morpholinyl, N—(C₁-C₆ alkyl)piperazinyl,        N—(COC₁-C₆ alkyl)piperazinyl, or N-aryl-piperazinyl ring system,

R¹¹ and R¹² are hydrogen.

Illustrating the first class of this second embodiment are the followingcompounds (with their Compound Number designation) of the formula (IIa):

R⁶ R¹ N(R⁸)R⁹ R⁴ Bu TET N(Me)iPr Me Pr TET N(Pn)₂ Me Pr TET N(Me)Pr BnPr TET N(Me)Et Bn Pr TET morpholino Bn Et TET NHPr Bn Pr TET N(Me)iPrBn-4-F Pr TET N(Me)iPr CH₂-2-Pyr

In a third specific embodiment of the compounds of the formula (IIa), R⁵is COR¹⁰. One class of this embodiment is represented by the compoundsof the formula (IIa) wherein:

R¹¹ is tetrazol-5-yl, SO₂NHCOR³ or NHSO₂CF₃;

R³ is

-   -   a) phenyl,    -   b) substituted phenyl in which the substituent is F, Cl, Br, I        or C₁-C₄ alkoxy,    -   c) C₁-C₈ alkyl substituted with di-(C₁-C₄ alkyl)amino or NH₂, or    -   d) C₃-C₇-cycloalkyl;

R⁴ is

-   -   a) C₂-C₆ alkyl,    -   b) substituted C₂-C₆ alkyl in which the substituent is: CHO,        CO₂C₁-C₄ alkyl, CO₂H, OC₁-C₄ alkyl, cyclohexyl, phenyl, or        NHCO₂tBu,    -   c) benzyl,    -   d) substituted benzyl in which the substituent on the phenyl        group is: F, Cl, Br, I, OH, OPO(OC₁-C₄ alkyl)₂, OPO(Obenzyl)₂,        OPO(OH)₂, —PO(OC₁-C₄ alkyl)₂, —PO(Obenzyl)₂, OPO(OH)₂, NO₂, NH₂,        N(C₁-C₄ alkyl)₂, Obenzyl, OC₁-C₄ alkyl, COOH, or CO₂CH₃,    -   e) CH₂-heteroaryl or    -   f) C₃-C₆ alkenyl;

R⁶ is

-   -   a) C₁-C₆ alkyl,    -   b) substituted C₁-C₆ alkyl in which the substituent is: -benzyl,        —C₁-C₃ alkyl, or —OC₁-C₄ alkyl or    -   c) cyclopropyl;

R¹⁰) is

-   -   (a) phenyl,    -   (b) substituted phenyl in which the substituent is F, Cl, Br, I,        methoxy, methyl, CF₃, SMe, SO₂Me, OH, OPO(O—C₁-C₄ alkyl)₂,        OPO(OH)₂, OPO(OBn)₂, CO₂C₁-C₄ alkyl, COOH, Obenzyl or OC₆H₅,    -   (c) benzyl,    -   (d) heteroaryl,    -   (e) C₁-C₆ alkyl or    -   (f) substituted C₁-C₆ alkyl substituted with: imidazole,        piperazine, morpholinyl, N—(C₁-C₆ alkyl)piperazinyl, N—(COC₁-C₆        alkyl)piperazinyl, or N-aryl-piperazinyl;

R¹¹ and R¹² are hydrogen.

Illustrating the first class of this third embodiment are the followingcompounds (with their Compound Number designation) of the formula (IIa):

R⁶ R¹ R¹⁰ R⁴ Pr TET Ph Pn Pr TET Bn Pn Pr TET 4-Pyr Pn Pr TET Ph Bn PrTET Ph-4-Cl Pn Pr TET Ph-4-Cl Pn Pr TET Ph-4-Ome 4- Methylpentyl Pr TET2-Furyl Pn Pr TET 3-methylbutyl Pr TET Bu Bn Pr TET Ph-4-F Pn Pr TETPh-4-F Bu Pr TET Ph-4-Me Pn Pr TET Ph-3-Br Pn Pr TET 3-MethylbutylBn-4-OH Pr TET Bu Bu Et TET Ph Bn Pr TET Ph-4-CF₃ Pn Et TET Ph-4-F Pn1-Methylpentyl TET Ph-4-F Pn Et TET Ph-4-F Bu Et TET Ph Bn-4-F cPr TETPh Bn cPr TET Ph Pn 1-Methyl-3- TET Ph Bn phenethyl cPr TET Ph Bn cPrTET Ph Bn Pr TET 4-Py Bu Me TET Ph Bn iPr TET Ph Bn Et SO₂NHBz Ph Bn PrTET 3-Pyr Pn Pr SO₂NHCOcPr Ph Pn Pr SO₂NHBz Ph Pn Et TET 4-Pyr Bn Pr TETPh-4-SMe Pn Pr TET Ph Pr Et TET Ph-2-Cl Bn Et TET Ph-2-Cl Bn-2-Cl Pr TETPh-4-SOMe Pn Pr TET Ph (CH₂)CHO Pr TET Ph-4-SO₂Me Pn Et TET Ph Bn-2-ClEt TET Ph CH₂CH═CMe₂ Pr SO₂NHCOcPr Me Pr Pr SO₂NHCOcPr cPr Pn PrSO₂NHCOcPr Me Pn Pr SO₂NHCOPh cPr Pr Pr TET Ph-4-F Pr Et TET Ph iPn iPrTET Ph Bn-2-Cl iPr TET cPr Bn iPr TET cPr Bn-2-Cl H TET Ph Bn H TET PhBn-2-Cl Et TET Ph Bn-4-Cl Et TET Ph Bn-4-F Et TET Ph -Bn-3-Et1-ethyl-ethyl TET Ph Bn 1-ethyl-ethyl TET Ph Bn-2-Cl Pr TET Ph iBu PrTET Ph (CH₂)₃CO₂Et Pr NHSO₂CF₃ Ph Pn Pr TET Ph (CH₂)₃CO₂H Me TET PhBn-2-Cl Me TET 4-Pyr Bn Pr SO₂NHCOcPr Me Me Pr TET Ph CH₂CO₂Et Me TET4-Pyr Bn-2-Cl Me TET 4-Pyr CH₂CH═CMe₂ Et TET Ph Bn-4-I Pr TET 2-thienylPn Pr TET 2-thienyl Me iPr TET Ph Bn-4-I Et TET Ph-4-I Bn Et TET PhBz-2-I Et TET 2-thienyl Bn Pr TET 4-Pyr (CH₂)₂)OMe Pr TET Ph CH₂CO₂HCH₂OMe TET Ph-4-Cl Pn Et TET 2-furoyl Bn Pr TET 2-thienyl Bn Pr TET2-thienyl Et Pr TET 2-furoyl Et Pr TET Ph-2-OMe Bn Pr TET Ph-2-OMe Pr PrTET Ph-4-OBn Pn Pr TET Ph-4-OBn Pr Pr TET Ph-4-OH Pn Pr TET Ph-4-OH PrPr TET CH₂imidazole Bn Pr TET CH₂PIPBoc Bn Pr TET 3-Pyr Bn Pr TET 2-PyrBn Pr TET Ph CH₂-2-Pyr Pr TET Ph CH₂-4-Pyr Pr TET 4-Pyr Bn Pr TET 2-PyrBn Pr TET Ph CH₂-3-Pyr Pr TET Ph CH₂-2-Pyr Pr TET Ph-4-OPO(OBn)₂ Pn PrTET Ph-4-OH Bu Pr TET 4-Pyr CH₂-2-Pyr Pr TET Ph-4-OP(OH)₂ Pn Pr TETPh-4-OH Bn Pr TET 2-furoyl CH₂-2-Pyr Pr TET Ph-4-OPO(ONa)₂ Bu

In a fourth embodiment of the compounds of the formula (IIa), R⁵ isSO₂R¹⁰. One class of this embodiment is represented by the compounds ofthe formula (IIa) wherein:

R¹ is tetrazol-5-yl, SO₂NHSO₂CF₃ or NHSO₂CF₃

R³ is

-   -   (a) phenyl,    -   (b) substituted phenyl in which the substituent is F, Cl, Br, I        or C₁-C₄ alkoxy,    -   (c) C₁-C₈ alkyl substituted with di-(C₁-C₄ alkyl)amino or NH₂,        or    -   (d) C₃-C₇-cycloalkyl;

R⁴ is

-   -   (a) C₂-C₆ alkyl,    -   (b) substituted C₁-C₆ alkyl in which the substituent is: CHO,        CO₂C₁-C₄ alkyl, CO₂H, OC₁-C₄ alkyl, cyclohexyl, phenyl, or        NHCO₂tBu,    -   (c) benzyl,    -   (d) substituted benzyl in which the substituent on the phenyl        group is: F, Cl, Br, I, OH, OPO(OC₁-C₄ alkyl)₂, OPO(Obenzyl)₂,        OPO(OH)₂, —PO(OC₁-C₄ alkyl)₂, —PO(Obenzyl)₂, —OPO(OH)₂, NO₂,        NH₂, N(C₁-C₄ alkyl)₂, or Obenzyl,    -   (e) CH₂-heteroaryl or    -   (f) C₃-C₆ alkenyl;

R⁶ is

-   -   (a) C₁-C₆ alkyl,    -   (b) substituted C₁-C₆ alkyl in which the substituent is:        -benzyl, —C₁-C₃ alkyl, or —OC₁-C₄ alkyl or,    -   (c) cyclopropyl;

R¹⁰ is

-   -   (a) phenyl,    -   (b) substituted phenyl in which the substituent is F, Cl, Br, I,        methoxy, methyl, CF₃, SMe, SOMe, SO₂Me, OH, OPO(O—C₁-C₄ alkyl)₂,        OPO(OH)₂, OPO(OBn)₂, CO₂C₁-C₄ alkyl, or COOH,    -   (c) benzyl,    -   (d) heteroaryl,    -   (e) C₁-C₆ alkyl, or    -   (f) substituted C₁-C₆ alkyl substituted with: imidazole,        piperazine, morpholinyl, N—(C₁-C alkyl)-piperazinyl, N—(COC₁-C₆        alkyl)-piperazinyl, or N-aryl-piperazinyl;

R¹¹ and R¹² are hydrogen.

Illustrating this class of the fourth embodiment is the followingcompounds (with its Example Number designation) of the formula (IIa):

R⁶ R¹ R¹⁰ R⁴ Pr TET Bu Bn Et TET Pr Pn Et TET Bu Pn Et TET Pr(CH₂)₃NHBoc Et TET Pr Bn

In still other embodiments, the AT₂ receptor antagonist is selected fromthe substituted quinazolinone compounds listed in U.S. Pat. No.5,441,959 and especially in the compound claims of this patent.Representative examples of such compounds are represented by the formula(IIIa):

or a pharmaceutically compatible salt thereof,

wherein:

R¹¹ is —SO₂NHCO₂R²³;

R³ is

-   -   (a) halogen (Cl, Br, I, F),    -   (b) C₁-C₄ alkyl, or    -   (c) CF₃;

R⁶ is straight chain C₁-C₄ alkyl;

R⁸ is

-   -   (a) R^(23′)    -   (b) NR²⁴R^(23′);

R²³ and R^(23′) are independently

-   -   (a) aryl, wherein aryl is defined as phenyl or naphthyl        unsubstituted or substituted with one or two substituents        selected from the group consisting of: halogen (Cl, Br, I, F),        N(R²⁴)₂, CO₂R²⁴, C₁-C₄ alkyl, C₁-C₄ alkoxyl, NO₂, CF₃, C₁-C₄        alkylthio, OH, —SO₂N(R²⁴)₂, C₃-C₇ cycloalkyl, C₃-C₁₀ alkenyl and        S(O)_(n)(C₁-C₄ alkyl); where n=1 or 2,    -   (b) heteroaryl, wherein heteroaryl is an unsubstituted or mono        or disubstituted heteroaromatic 5- or 6-membered ring which can        contain one or two heteroatoms selected from the group        consisting of N, O and S and wherein the substituents are        members selected from the group consisting of —OH, —SH, C₁-C₄        alkyl, C₁-C₄ alkoxy, CF₃, halogen (Cl, Br, I, F) and NO₂,    -   (c) C₃-C₇ cycloalkyl,    -   (d) C₁-C₆ alkyl optionally substituted with a substituent        selected from the group consisting of aryl as defined above,        heteroaryl as defined above, —OH, —SH, C₁-C₄ alkyl, —O(C₁-C₄        alkyl), C₃-C₇ cycloalkyl, —S(O)_(n) (C₁-C₄ alkyl), —CF₃, halogen        (Cl, Br, F, I), —NO₂, —CO₂H, CO₂—(C₁-C₄ alkyl), —NH₂, —NH(C₁-C₄        alkyl), —N(C₁-C₄ alkyl)₂, or    -   (e) perfluoro-C₁-C₄ alkyl; and

R²⁴ is

-   -   (a) H,    -   (b) C₁-C₄ alkyl, unsubstituted or substituted with aryl as        defined above or heteroaryl as defined above, or    -   (c) aryl; and

R^(23′) and R²⁴ when taken together may form a morpholine or piperazinering, wherein the piperazine ring may be substituted on the nitrogenwith C₁-C₄ alkyl or C₁-C₄ acyl.

One embodiment of the compounds of formula (IIIa) are those wherein:

R³ is

-   -   (a) F,    -   (b) Me, or    -   (c) CF₃;

R⁶ is straight chain C.sub.1-C.sub.4 alkyl;

R⁸ is R^(23′);

R^(23′) is

-   -   (a) aryl, wherein aryl is defined as phenyl or naphthyl        unsubstituted or substituted with one or two substituents        selected from the group consisting of: halogen (Cl, Br, I, F),        N(R²⁴)₂, CO₂R²⁴, C₁-C₄ alkyl, C₁-C₄ alkoxyl, NO₂, CF₃, C₁-C₄        alkylthio, OH, —SO₂N(R²⁴)₂, C₃-C₇ cycloalkyl, C₃-C₁₀ alkenyl and        S(O)_(n) (C₁-C₄ alkyl); where n=1 or 2,    -   (b) heteroaryl, wherein heteroaryl is an unsubstituted or mono-        or disubstituted heteroaromatic 5- or 6-membered ring which can        contain one or two heteroatoms selected from the group        consisting of N, O and S and Wherein the substituents are        members selected from the group consisting of —OH, —SH, C₁-C₄        alkyl, C₁-C₄ alkoxy, CF₃, halogen (Cl, Br, I, F) and NO₂,    -   (c) C₁-C₆ alkyl unsubstituted or substituted with a substituent        selected from the group consisting of aryl as defined above,        heteroaryl as defined above, —OH, —SH, C₁-C₄ alkyl, —O(C₁-C₄        alkyl), C₃-C₇ cycloalkyl, —CF₃, halogen (Cl, Br, F, I), —N(C₁-C₄        alkyl)₂, or C₃-C₇ cycloalkyl; and

R²³ is

-   -   (a) C₁-C₆-alkyl, unsubstituted or substituted with a substituent        selected from the group consisting of: aryl as defined above,        heteroaryl as defined above, C₁-C₄ alkyl, CF₃, —O(C₁-C₄ alkyl),        C₃-C₇ cycloalkyl, or    -   (b) perfluoro-C₁-C₄-alkyl.

This embodiment is exemplified further by:

R²³ R³ R⁶ R⁸ iPn F Pr Ph iPn F Pr -2-furoyl iPn F Bu Et iPn F Bu Pr iPnF Pr CH₂OCH₂CH₃ iPn F Et -2-furoyl iPn F Et Ph iPn F Et -3-pyridyl iPn FEt -4-pyridyl iPn F Et -2-pyridyl (CH₂)₂cPr F Et Ph (CH₂)₂cPr F Et-2-furoyl

wherein:

Et is ethyl,

Pr is n-propyl,

cPr is cyclopropyl,

Bu is n-butyl,

iPn is 3-methylbutyl, and

Ph is phenyl.

A second embodiment of structures of formula (IIIa) are those whereinR²³, R³, R⁶ are as recited in the first embodiment and all othersubstituents are as recited below:

R⁸ is —NR²⁴R^(23′);

R^(23′) is C₁-C₆ alkyl which is unsubstituted or substituted with asubstituent selected from the group aryl, heteroaryl, C₁-C₄ alkyl,—O(C—C₄ alkyl), CF₃, NH(C₁-C₄ alkyl), N(C₁-C₄ alkyl)₂, C₃-C₇ cycloalkyl;

R²⁴ is

-   -   (a) C₁-C₆ alkyl which is unsubstituted or substituted with aryl        or heteroaryl, or    -   (b) H; and

R^(23′) and R²⁴ when taken together may form a morpholine or piperazinering,

wherein the piperazine ring may be substituted on the nitrogen withC₁-C₄ alkyl or C₁-C₄ acyl.

Compounds exemplifying this embodiment include:

R²³ R³ R⁶ R^(23′) R²⁴ iPn Me Pr iPr H Bu Me Pr iPr H Bu F Pr iPr H iPn FPr iPr H iPn Me Pr iPr H Bu F Bu iPr Me iPn F Pr iPr H (CH₂)₂cPr F BuiPr Me (CH₂)₂cPr F Et Et H Me F Et Et H iPn F Pr morpholino iPn F Bu iPrMe iPn F Et iPr Me iPn F Et morpholino Bu F Et morpholino iPn F Bupiperazinyl-4-methyl Bu F Et iPr Me (CH₂)₂tBu F Pr iPr H tBu F Pr iPr HiPr F Pr Me Me iHex F Et morpholino iPn F Et Me Me (CH₂)₂cPr F Et iPr H(CH₂)₂cPr F Et iPr Me iPn F Me iPr H iPn F Me iPr Me (CH₂)₂cPr F Me MeMe iBu F Et iPr Me iPn F Et iPr Me

wherein:

Me is methyl,

Et is ethyl,

Pr is n-propyl,

cPr is cyclopropyl,

iPr is isopropyl,

Bu is n-butyl,

iBu is isobutyl,

tBu is t-butyl,

iPn is 3-methylbutyl, and

iHex is 4-methylpentyl.

In the above embodiments described above for compounds according toformula (IIIa), the heteroaryl substituent represents any 5 or6-membered aromatic ring containing from one to three heteroatomsselected from the group consisting of nitrogen, oxygen, and sulfur, forexample, pyridyl, thienyl, furyl, pyrazolyl, pyrrolyl, imidazolyl,pyridazinyl, pyrimidinyl, pyrazinyl, isoxazolyl, isothiazolyl, oxazolyl,triazolyl and thiazolyl.

In still other embodiments, the AT₂ receptor antagonist is selected fromthe imidazole compounds listed in U.S. Pat. No. 5,545,651 and especiallyin the compound claims of this patent. Representative examples of suchcompounds are represented by the formula (IVa):

wherein:

R¹ is in the meta or para position and is

-   -   (a) 4-CO₂H,    -   (b) —CH₂CO₂H,    -   (c) —C(CF₃)₂OH,    -   (d) —CONHNHSO₂CF₃,    -   (e) 4-CONHCH(CO₂H)CH₂C₆H₅(L-isomer),    -   (f) 4-CONHOR¹²,    -   (g) —CONHSO₂R¹⁰,    -   (h) —CONHSO₂NHR⁹,    -   (i) —C(OH)R⁹PO₃H₂,    -   (j) —NHCOCF₃,    -   (k) —NHCONHSO₂R¹⁰,    -   (l) —NHPO₃H₂,    -   (m) 4-NHSO₂R¹⁰,    -   (n) —NHSO₂NHCOR¹⁰,    -   (O) —OPO₃H₂,    -   (p) —OSO₃H,    -   (q) —PO₃H₂,    -   (r) —PO(OH)R⁹,    -   (s) —SO₃H,    -   (t) —SO₂NHR⁹,    -   (u) —SO₂NHCOR¹⁰,    -   (v) —SO₂NHCONHR⁹,

-   -   (ii) —SO₂NHCO₂R¹⁰,

R² is independently

-   -   (a) H,    -   (b) halo (F, Cl, Br, I),    -   (c) C₁-C₄-alkyl,    -   (d) C₁-C₄alkoxy,    -   (e) C₁-C₄-acyloxy,    -   (f) C₁-C₄-alkylthio,    -   (g) C₁-C₄-alkylsulfinyl,    -   (h) C₁-C₄-alkylsulfonyl,    -   (i) —(C₁-C₄-alkyl)-OH,    -   (j) —(C₁-C₄) alkyl-aryl,    -   (k) —CO₂H,    -   (l) —CN,    -   (m) tetrazol-5-yl,    -   (n) —CONHOR¹²,    -   (o)—SO₂NHR⁹,    -   (p) —NH₂,    -   (q) C₁-C₄-alkylamino,    -   (r) C₁-C₄-dialkylamino,    -   (s) —NHSO₂R¹⁰,    -   (t) —NO₂,    -   (u) furyl,    -   (v) phenyl or phenyl optionally substituted with one or two        substituents selected from the group consisting of halo,        C₁-C₄-alkyl, C₁-C₄-alkoxy, —NO₂, —CF₃, C₁-C₄-alkylthio, —OH,        —NH₂, C₁-C₄-alkylamino, C₁-C₄-dialkylamino, —CN, —CO₂R¹²,        acetyl;

R³ is independently

-   -   (a) H,    -   (b) halo,    -   (c) C₁-C₄-alkyl,    -   (d) C₁-C₄-alkoxy, or    -   (e) —C₁-C₄-alkyl-(C₁-C₄-alkoxy);

R⁴ is

-   -   (a) —CN,    -   (b) —NO₂, or    -   (c) —CO₂R¹¹;

R⁵ is

-   -   (a) H,    -   (b) C₁-C₆-alkyl,    -   (c) C₃-C₆-cycloalkyl,    -   (d) C₂-C₄-alkenyl, or    -   (e) C₂-C₄-alkynyl;

R⁶ is

-   -   (a) C₁-C₁₀-alkyl,    -   (b) C₃-C₁₀-alkenyl,    -   (c) C₃-C₁₀-alkynyl,    -   (d) C₃-C₈-cycloalkyl,    -   (e) C₃-C₄-cycloalkenyl,    -   (f) —C₁-C₃-alkyl-(C₃-C₈-cycloalkyl),    -   (g) —C₁-C₃-alkenyl-(C₅-C₁₀-cycloalkyl),    -   (h) —C₁-C₃-alkynyl-(C₅-C₁₀-cycloalkyl),    -   (i) —(CH₂)_(s)S(CH₂)_(m)R⁵, or    -   (j) benzyl, optionally substituted on the phenyl ring with 1-2        substituents selected from the group consisting of halo,        C₁-C₄-alkyl, C₁-C₄-alkoxy or —NO₂;

R⁷ is

-   -   (a) C₁-C₆-alkyl,    -   (b) C₃-C₆-cycloalkyl,    -   (c) aryl, or    -   (d) benzyl, optionally substituted on the phenyl ring with 1-2        substituents selected from the group consisting of halo,        C₁-C₄-alkyl, C₁-C₄-alkoxy or —NO₂;

R⁸ is

-   -   (a) H,    -   (b) halogen (F, Cl, Br, I),    -   (c) phenyl, or phenyl optionally substituted with halogen (F,        Cl, Br, I), C₁-C₄-alkyl, —OH, C₁-C₄-alkoxy, —NO₂, —NR²⁶R²⁷,        —NR²⁶COR¹¹, —NR²⁶CO₂R⁷, —S(O)_(r)R¹⁰, —SO₂NR²⁶R²⁷, —NR²⁶CF₃,    -   (d) C₁-C₆-alkyl, optionally substituted with        -   i) OR²⁵,        -   ii) S(O)_(r)R¹⁰,        -   iii) NR²³R²⁴,        -   iv) NR²⁶COR¹¹,        -   v) NR²⁶CO₂R⁷,

vi) NR²⁶CONR²³R²⁴,

vii) OCONR²³R²⁴,

viii) OCOR¹¹,

ix) aryl,

-   -   (e) C₂-C₄-alkenyl,    -   (f) —C₁-C₄-alkyl-aryl,    -   (h) C₁-C₄-alkoxy,    -   (i) C_(v)F_(2v+1) where v=1 to 3,    -   (j) —S(O)_(r)R¹⁰,    -   (k) —S(O)₂NR²³R²⁴,    -   (l) —CONR²³R²⁴,    -   (m) —COR⁷, or    -   (n) —CO₂R¹²;

R⁹ is

-   -   (a) H,    -   (b) C₁-C₅-alkyl,    -   (c) aryl,    -   (d) —(C₁-C₄-alkyl)-aryl,    -   (e) heteroaryl, or    -   (f) C₃-C₅-cycloalkyl;

R¹⁰ is

-   -   (a) aryl,    -   (b) C₃-C₇-cycloalkyl,    -   (c) C₁-C₄-perfluoroalkyl,    -   (d) C₁-C₁-alkyl, optionally substituted with a substituent        selected from the group consisting of aryl, heteroaryl, —OH,        —SH, C₁-C₄-alkyl, C₁-C₄-alkoxy, C₁-C₄-alkylthio, —CF₃, halo,        —NO₂, —CO₂R¹², —NH₂, C₁-C₄-alkylamino, C₁-C₄-dialkylamino,        —PO₃H₂, or    -   (e) heteroaryl;

R¹¹, R^(11a) and R^(11b) are independently

-   -   (a) H,    -   (b) C₁-C₆-alkyl,    -   (c) C₃-C₆-cycloalkyl,    -   (d) aryl,    -   (e) —(C₁-C₅-alkyl)-aryl, or    -   (f) heteroaryl;

R¹² is

-   -   (a) H,    -   (b) methyl, or    -   (c) benzyl, optionally substituted on the phenyl ring with 1-2        substituents selected from the group consisting of halo,        C₁-C₄-alkyl, C₁-C₄-alkoxy or —NO₂;

R¹³ is

-   -   (a) —CO₂H,    -   (b) —CH₂CO₂H,    -   (c) —C(CF₃)₂OH,    -   (d) —CONHNHSO₂CF₃,    -   (e) —CONHOR¹²,    -   (f) —CONHSO₂R¹⁰,    -   (g) —CONHSO₂NHR⁹,    -   (h) —C(OH)R⁹PO₃H₂,    -   (i) —NHCOCF₃,    -   (j) —NHCONHSO₂R¹⁰,    -   (k) —NHPO₃H₂,    -   (l) —NHSO₂R¹⁰,    -   (m) —NHSO₂NHCOR¹⁰,    -   (n) —OPO₃H₂,    -   (o) —OSO₃H,    -   (p) —PO(OH)R⁹,    -   (q) —PO(OH)₂,    -   (r) —SO₃H,    -   (s) —SO₂NHR⁹,    -   (t) —SO₂NHCOR¹⁰,    -   (u) —SO₂NHCONHR⁹,    -   (v) —SO₂NHCO₂R¹⁰,

R¹⁴ is

-   -   (a) H,    -   (b) C₁-C₆-alkyl,    -   (c) —CH₂CH═CH₂, or    -   (d) benzyl, optionally substituted on the phenyl ring with 1-2        substituents selected from the group consisting of halo,        C₁-C₄-alkyl, C₁-C₄-alkoxy or —NO₂;

R¹⁵ is

-   -   (a) H,    -   (b) C₁-C₈-alkyl,    -   (c) C₁-C₈-perfluoroalkyl,    -   (d) C₃-C₆-cycloalkyl,    -   (e) aryl, or    -   (f) benzyl, optionally substituted on the phenyl ring with 1-2        substituents selected from the group consisting of halo,        C₁-C₄-alkyl, C₁-C₄-alkoxy or —NO₂;

R¹⁶ is

-   -   (a) H,    -   (b) C₁-C₆-alkyl, or    -   (c) benzyl, optionally substituted on the phenyl ring with 1-2        substituents selected from the group consisting of halo,        C₁-C₄-alkyl, C₁-C₄-alkoxy or —NO₂;

R¹⁷ is

-   -   (a) 11,    -   (b) C₁-C₆-alkyl,    -   (c) C₃-C₆-cycloalkyl,    -   (d) aryl, or    -   (e) benzyl, optionally substituted on the phenyl ring with 1-2        substituents selected from the group consisting of halo,        C₁-C₄-alkyl, C₁-C₄alkoxy or —NO₂;

R¹⁸ is

-   -   (a) —NR¹⁹R²⁰    -   (b) —NHCONH₂,    -   (c) —NHCSNH₂, or    -   (d) —NHSO₂—C₆H₅;

R¹⁹ and R²⁰ are independently

-   -   (a) H,    -   (b) CC₁-C₅-alkyl, or    -   (c) aryl,

R²¹ and R²² are independently

-   -   (a) C₁-C₄-alkyl, or taken together are    -   (b) —(CH₂)_(q)—;

R²³ and R²⁴ are, independently

-   -   (a) H,    -   (b) C₁-C₆-alkyl,    -   (c) aryl, or    -   (d) —(C₁-C₄-alkyl)-aryl, or    -   (e) R²³ and R²⁴ when taken together constitute a pyrrolidine,        piperidine or morpholine ring;

R²⁵ is

-   -   (a) H,    -   (b) C₁-C₄-alkyl,    -   (c) aryl,    -   (d) —(C₁-C₄-alkyl)-aryl,    -   (e) C₃-C₆-alkenyl, or    -   (f) —(C₃-C₆-alkenyl)-aryl;

R²⁶ and R²⁷ are independently

-   -   (a) H,    -   (b) C₁-C₄-alkyl,    -   (c) aryl, or    -   (d) —C₂-aryl;

R²⁸ is

-   -   (a) aryl, or    -   (b) heteroaryl;

R²⁹ is

-   -   (a) —CHO,    -   (b) —CONH₂,    -   (c) —NHCHO,    -   (d) —CO—(C₁-C₆ perfluomalkyl),    -   (e) —S(O)_(r)—(C₁-C₆ perfluoroalkyl),    -   (f) —O—(C₁-C₆₆ perfluoroalkyl), or    -   (g) —NR^(11a)—(C₁-C₆ perfluoroalkyl);

R³⁰ is

-   -   (a) —CHO,    -   (b) —SO₂—(C₁-C₆ perfluoroalkyl), or    -   (c) —CO—(C₁-C₆ perfluoroalkyl);

A is

-   -   (a) —(CH₂)_(n)-L¹-B-(T)_(y)-(B)_(y)-X²-(B)_(y)-R²⁸,    -   (b) —(CH₂)_(n)-L¹-B-T-(B)_(y)-R²⁸,    -   (c) —(CH₁)_(n)-L-B-(T)_(y)-(B)_(y)-X²-B,    -   (d) —(CH₂)_(n)-L-B-T-(B)_(y)-R²⁹,    -   (e) —(CH₂)_(n)-L¹-T-(B)_(y)-X² (B)_(y)-R²⁸,    -   (f) —(CH₂)_(n)-L¹-T-(B)_(y)-R²⁸,    -   (g) —(CH₂)_(n)-L¹-T-(B)_(y)-X²-B,    -   (h) —(CH₂)_(n)-L¹-(CR¹⁹R.²⁰)-D-(T)_(y)-(B)_(y)-X³-(B)_(y)-R²⁸,    -   (i) —(CH₂)_(n)-L¹-(CR¹⁹R.²⁰)-D-T-(B)_(y)-R²⁸,    -   (j) —(CH₂)_(n)-L¹-(CR¹⁹R.²⁰)-D-(T)_(y)-(B)_(y)-X³-B,    -   (k) —(CH₂)_(n)-L¹-(CR¹⁹R²⁰)-D-T-(B)_(y)-R²⁹,    -   (l) —(CH₂)_(n)-L¹-(CR¹⁹R.²⁰)-D-T-(B)_(y)-X⁴-(B)_(y)-R²⁸    -   (m) —(CH₂)_(n)-L¹-(CR¹⁹R.²⁰)-D-B-X⁴-(B)_(y)-R²⁸,    -   (n) —(CH₂)_(n)-L¹-(CR¹⁹R.²⁰)-D-T-(B)_(y)-X⁴-B,    -   (o) —(CH₂)_(n)-L¹-(CR¹⁹R.²⁰)-D-B-X⁴-B,    -   (p) —(CH₂)_(n)-L²-B-(T)_(y)-(B)_(y)-X²-(B)_(y)-R²⁸,    -   (q) —(CH₂)_(n)-L²-B-T-(B)_(y)-R²⁸,    -   (r) —(CH₂)_(n)-L²-B-(T)_(y)-(B)_(y)-X²-B,    -   (s) —(CH₂)_(n)-L²-B-T-(B)_(y)-R²⁹,    -   (t) —(CH₂)_(n)-L²-T-(B)_(y)-X²-(B)_(y)-R²⁸,    -   (u) —(CH₂)_(n)-L²-T-(B)_(y)-R²⁸,    -   (v) —(CH₂)_(n)-L²-T-(B)_(y)-X²-B,    -   (w) —(CH₂)_(n)-L²-D-(T)_(y)-(B)_(y)-X³-(B)_(y)-R²⁸,    -   (x) —(CH₂)_(n)-L²-D-T-(B)_(y)-R²⁸,    -   (y) —(CH₂)_(n)-L²-D-(T)_(y)-(B)_(y)-X³-B,    -   (z) —(CH₂)_(n)-L²-D-T-(B)_(y)-R²⁹,    -   (aa) —(CH₂)_(n)-L²-D-T-(B)_(y)-X⁴-(B)_(y)-R²⁸,    -   (bb) —(CH₂)_(n)-L²-D-B-X⁴-(B)_(y)-R²⁸,    -   (cc) —(CH₂)_(n)-L²-D-T-(B)_(y)-X⁴-B,    -   (dd) —(CH₂)_(n)-L²-D-B-X⁴-B,    -   (ee) —(CH₂)_(m)-L³-B-(T)_(y)-(B)_(y)-X²-(B)_(y)-R²⁸,    -   (ff) —(CH₂)_(m)-L³-B-T-(B)_(y)-R²⁸,    -   (gg) —(CH₂)_(m)-L³-B-(T)_(y)-(B)_(y)-X²-B,    -   (hh) —(CH₂)_(m)-L³-B-T-(B)_(y)-R²⁹,    -   (ii) —(CH₂)_(m)-L³-T-(B)_(y)-X²-(B)_(y)-R²⁸,    -   (jj) —(CH₂)_(m)-L³-T-(B)_(y)-R²⁸,    -   (kk) —(CH₂)_(m)-L³-T-(B)_(y)-X²-B,    -   (ll) —(CH₂)_(m)-L³-(CR¹⁹R²⁰)-D-(T)_(y)-(B)_(y)-X³-(B)_(y)-R²⁸,    -   (mm) —(CH₂)_(m)-L³-(CR¹⁹R²⁰)-D-T-(B)_(y)-R²⁸,    -   (nn) —(CH₂)_(m)-L³-(CR¹⁹R²⁰)-D-(T)_(y)-(B)_(y)-X³-B,    -   (oo) —(CH₂)_(m)-L³-(CR¹⁹R²⁰)-D-T-(B)_(y)-R²⁹,    -   (pp) —(CH₂)_(m)-L³-(CR¹⁹R.²⁰)-D-T-(B)_(y)-X⁴-(B)_(y)-R²⁸,    -   (qq) —(CH₂)_(m)-L³-(CR¹⁹R.²⁰)-D-(B)-X⁴-(B)_(y)-R²⁸,    -   (rr) —(CH₂)_(m)-L³-(CR¹⁹R.²⁰)-D-T-(B)_(y)-X⁴-B,    -   (ss) —(CH₂)_(m)-L³-(CR¹⁹R.²⁰)-D-B-X⁴-B,

L¹ is

-   -   (a) —CO₂—,    -   (b) —CONR^(11a)—,    -   (c) —NR^(11a)CO₂—, or    -   (d) —NR^(11a)CONR^(11b)—;

L² is

-   -   (a) —CO—,    -   (b) NR^(11a)CO—, or    -   (c) —O₂C—;

L₃ is

-   -   (a) —O—,    -   (b) —SO—, or    -   (c) —NR^(11a)—;

B is C₁-C₆ alkyl;

D is C₂-C₈ alkenyl or C₂-C₈ alkynyl;

T is

-   -   (a) arylene, or    -   (b) heteroarylene

X¹ is

-   -   (a) a carbon-carbon single bond,    -   (b) —CO—,    -   (c) —C(R¹⁹)(R²⁰)—,    -   (d) —O—,    -   (e) —S—,    -   (f) —SO—,    -   (g) —SO₂—,    -   (h) —NR¹⁴—,    -   (i) —CONR¹⁶—,    -   (j) —NR¹⁶CO—,    -   (k) —OC(R¹⁹)(R²⁰)—,    -   (l) —C(R¹⁹)(R²⁰)O—,    -   (m) —SC(R¹⁹)(R²⁰)—,    -   (n) —C(R¹⁹)(R²⁰)S—,    -   (o) —NHC(R¹⁹)(R²⁰)—,    -   (p) —C(R¹⁹)(R²⁰)NH—,    -   (q) —NR¹⁶SO₂—,    -   (r) —SO₂NR¹⁶—,    -   (s) —CH═CH—,    -   (t) —CF═CF—,    -   (u) —CF═CH—,    -   (v) —CH═CF—,    -   (w) —CF₂CF₂—,    -   (x) —CH(OR¹⁵)—,    -   (y) —CH(OCOR¹⁷)—,    -   (z) —C(═NR¹⁸)—,    -   (aa) —C(OR²¹)(OR²²)—,    -   (bb) 1,2-cyclopropyl, or    -   (cc) 1,1-cyclopropyl;

X² is

-   -   (a) —CO—,    -   (b) —O—,    -   (c) —S(O)_(r)—,    -   (d) —(C.sub.1-C.sub.4-alkylene)-,    -   (e) —NR^(11a)CONR^(11a)—,    -   (l) —CONR^(11a)—,    -   (g) —NR^(11a)CO—,    -   (h) —SO₂NR¹⁶—,    -   (i) —NR¹⁶SO₂—,    -   (j) —OCONR^(11a)SO₂—,    -   (k) —SO₂NR^(11a)CO—,    -   (l) —SO₂NR^(11a)CO—,    -   (m) —OCONR^(11a)SO₂—,    -   (n) —SO₂NR^(11a)CONR^(11b)—,    -   (o) —NR^(11a)CONR^(11b)SO₂—,    -   (p) —SO₂NR^(11a)SO₂—,    -   (q) —CONR^(11a)SO₂NR^(11b)—, or    -   (r) —NR^(11a)SO₂NR^(11b)CO—;    -   X³ is    -   (a) —C—,    -   (b) —SO—,    -   (c) —SO₂—,    -   (d) single bond,    -   (e) —CONR^(11a)—,    -   (f) —SO₂NR¹⁶—,    -   (g) —CONR^(11a)SO₂—,    -   (h) —SO₂NR^(11a)CO—,    -   (i) —SO₂NR^(11a)CO₂—,    -   (j) —SO₂NR^(11a)CONR^(11a)—,    -   (k) —SO₂NR^(11a)SO₂—, or    -   (l) —CONR^(11a)SO₂NR^(11b)—;

X⁴ is

-   -   (a) —NR^(11a)CONR^(11b)—,    -   (b) —OCONR^(11a)SO₂,    -   (c) —NR¹⁶SO₂—,    -   (d) —OCONR^(11a)SO₂,    -   (e) —NR^(11a)CONR^(11b)SO₂—, or    -   (f) —NR^(11a)SO₂NR^(11b)CO—;

X⁵ is

-   -   (a) —CO—,    -   (b) —SO₂—,    -   (c) —COO—, or    -   (d) —CONR^(11a)—;

Z is

-   -   (a) —O—,    -   (b) —S—, or    -   (c) —NR¹¹—;    -   k is 1 or 2;    -   m is 1 to 5;    -   n is 0 to 2;    -   q is 2 to 3;    -   r is 0 to 2;    -   s is 0 to 5;    -   t is 0 to 3;    -   u is 2 to 5;    -   y is 0 or 1;

and pharmaceutically compatible salts of these compounds.

In specific embodiments, the above compounds are those of formula (IVa)wherein

A is

-   -   (a) —(CH₂)_(n)-L¹-S-(T), —(S)_(y)—X²—(S)_(y)—R²⁸,    -   (b) —(CH₂)_(n)-L¹-B-T-(B)_(y)-R²⁸,    -   (c) —(CH₂)_(n)-L-B-(T)_(y)-(B)_(y)-X²-B,    -   (d) —(CH₂)_(n)-L¹-B-T-(B)_(y)-R²⁹    -   (e) —(CH₂)_(n)-L²-B-(T)_(y)-(B)_(y)-X²-(B)_(y)-R²⁸,    -   (f) —(CH₂)_(n)-L²-B-T-(B)_(y)-R²⁸, or    -   (g) —(CH₂)_(n)-L²-B-(T)_(y)-(B)_(y)-X²-B,    -   (h) —(CH₂)_(n)-L²-B-T-(B)_(y)-R²⁹;

An illustrative example of the specific embodiments described above is acompound of formula (Va)

wherein

R² is independently

-   -   (a) H,    -   (b) halo (F, Cl, Br, I), or    -   (c) C₁-C₄-alkyl;

R³ is

-   -   (a) H, or    -   (b) halo (F, Cl, Br, I);

R⁶ is

-   -   (a) C₁-C₁₀ alkyl,    -   (b) C₃-C₁₀ alkenyl, or    -   (c) C₃-C₁₀ alkynyl;

R⁹ is

-   -   (a) H,    -   (b) C₁-C₅-alkyl,    -   (c) aryl,    -   (d) —(C₁-C₄-alkyl)-aryl, or    -   (e) heteroaryl;

R¹⁰ is

-   -   (a) aryl,    -   (b) C₃-C₇-cycloalkyl,    -   (c) C₁-C₄-perfluoroalkyl,    -   (d) C₁-C₄-alkyl, optionally substituted with a substituent        selected from the group consisting of aryl, heteroaryl, —OH,        —SH, C₁-C₄ alkyl, C₁-C₄-alkoxy, C₁-C₄-alkylthio, —CF₃, halo,        —NO₂, —CO₂R¹², —NH₂, C₁-C₄-alkylamino, C₁-C₄-dialkylamino,        —PO₃H₂, or    -   (e) heteroaryl;

R¹¹, R^(11a) and R^(11b) are independently

-   -   (a) H,    -   (b) C₁-C₆-alkyl,    -   (c) C₃-C₆-cycloalkyl,    -   (d) aryl,    -   (e) —(C₁-C₅-alkyl)-aryl, or    -   (f) heteroaryl;

R¹³ is

-   -   (a) —CO₂H,    -   (b) —CONHSO₂R¹⁰,    -   (c) —CONHSO₂NHR⁹,    -   (d) —NHCONHSO₂R¹⁰,    -   (e) —NHSO₂R¹⁰,    -   (f) —NHSO₂NHCOR¹⁰,    -   (g) —SO₂NHR⁹,    -   (h) —SO₂NHCOR¹⁰    -   (i) —SO₂NHCONHR⁹,    -   (j) —SO₂NHCO₂R¹⁰, or

R¹⁶ is

-   -   (a) H,    -   (b) C₁-C₆-alkyl, or    -   (c) benzyl, optionally substituted on the phenyl ring with 1-2        substituents selected from the group consisting of halo,        C₁-C₄-alkyl, C₁-C₄-alkoxy or —NO₂;

R²⁸ is

-   -   (a) aryl, or    -   (b) heteroaryl;

R²⁹ is

-   -   (a) —CHO,    -   (b) —CONH₂,    -   (c) —NHCHO,    -   (d) —CO—(C₁-C₆ perfluomalkyl),    -   (e) —S(O)_(r)—(C₁-C₆ perfluoroalkyl),

E is

-   -   (a) -(T)_(y)-(B)_(y)-X²-(B)_(y)-R²⁸,    -   (b) -T-(B)_(y)-R²⁸,    -   (c) -(T)_(y)-(B)_(y)-X²-B or,    -   (d) -T-(B)_(y)-R²⁹;

L¹ is

-   -   (a) —CO₂—,    -   (b) —CONR^(11a)—,    -   (c) —NR^(11a)CO₂—,    -   (d) —NR^(11a)CONR^(11b)—;

B is C₁-C₆ alkyl;

-   -   X² is    -   (a) —CO—,    -   (b) —O—,    -   (c) —S(O)_(r)—,    -   (d) —(C₁-C₄-alkylene)-,    -   (e) —NR^(11a)CONR^(11b)—,    -   (f) —CONR^(11a)—,    -   (g) —NR^(11a)CO—,    -   (h) —SO₂NR¹⁶—,    -   (i) —NR¹⁶SO₂—,    -   (j) —CONR^(11a)SO₂—,    -   (k) —SO₂NR^(11a)CO—,    -   (l) —SO₂NR^(11a)CO₂—,    -   (m) —OCONR^(11a)SO₂—,    -   (n) —SO₂NR^(11a)CONR^(11b)—,    -   (o) —NR^(11a)CONR^(11b)SO₂—,    -   (p) —SO₂NR^(11a)SO₂—,    -   (q) —CONR^(11a)SO₂NR^(11b)—, or    -   (r) —NR^(11a)SO₂NR^(11b)CO—,

and pharmaceutically compatible salts of these compounds.

Another illustrative example of the specific embodiments described aboveis a compound of formula (VIa)

wherein

R² is independently

-   -   (a) H,    -   (b) halo (F, Cl, Br, I), or    -   (c) C₁-C₄-alkyl;

R³ is

-   -   (a) H, or    -   (b) halo (F, Cl, Br, I);

R⁶ is

-   -   (a) C₁-C₁₀ alkyl,    -   (b) C₃-C₁₀ alkenyl, or    -   (c) C₃-C₁₀ alkynyl;

R⁹ is

-   -   (a) H,    -   (b) C₁-C₅-alkyl,    -   (c) aryl    -   (d) —(C₁-C₄-alkyl)-aryl, or    -   (e) heteroaryl;

R¹⁰ is

-   -   (a) aryl,    -   (b) C₃-C₇-cycloalkyl,    -   (c) C₁-C₄-perfluoroalkyl,    -   (d) C₁-C₄-alkyl, optionally substituted with a substituent        selected from the group consisting of aryl, heteroaryl, —OH,        —SH, C₁-C₄-alkyl, C₁-C₄-alkoxy, C₁-C₄-alkylthio, —CF₃, halo,        —NO₂, —CO₂R¹², C₁-C₄alkylamino, C₁-C₄-dialkylamino, —PO₃H₂, or    -   (e) heteroaryl;

R¹¹, R^(11a) and R^(11b) are independently

-   -   (a) H,    -   (b) C₁-C₆-alkyl,    -   (c) C₃-C₆-cycloalkyl,    -   (d) aryl,    -   (e) —(C₁-C₅-alkyl)-aryl, or    -   (f) heteroaryl;

R¹³ is

-   -   (a) —CO₂H,    -   (b) —CONHSO₂R¹⁹,    -   (c) —CONHSO₂NHR⁹,    -   (d) —NHCONHSO₂R¹⁰,    -   (e) —NHSO₂R¹⁰,    -   (f) —NHSO₂NHCOR¹⁰,    -   (g) —SO₂NHR⁹,    -   (h) —SO₂NHCOR¹⁰,    -   (i) —SO₂NHCONHR⁹,    -   (j) —SO₂NHCO₂R¹⁰, or

R¹⁶ is

-   -   (a) H,    -   (b) C₁-C₆-alkyl, or    -   (c) benzyl, optionally substituted on the phenyl ring with 1-2        substituents selected from the group consisting of halo,        C₁-C₄-alkyl, C₁-C₄-alkoxy or —NO₂;

R²⁸ is

-   -   (a) aryl, or    -   (b) heteroaryl;

R²⁹ is

-   -   (a) —CHO,    -   (b) —CONH₂,    -   (c) —NHCHO,    -   (d) —CO—(C₁-C₆ perfluoroalkyl),    -   (e) —S(O)_(r)—(C₁-C₆ perfluoroalkyl),

G is

-   -   (a) -(T)_(y)-(B)_(y)-X²-(B)_(y)-R²⁸,    -   (b) -T-(B)_(y)-R²⁸,    -   (c) -(T)_(y)-(B)_(y)-X²-B, or    -   (d) -T-(B)_(y)-R²⁹;

L² is —CO—, —NR^(11a)CO— or —O₂C—;

B is C₁-C₆ alkyl;

X₂ is

-   -   (a) —CO—,    -   (b) —O—,    -   (c) —S(O)_(r)—,    -   (d) —(C₂-C₄-alkylene)-,    -   (e) CO, —NR^(11a)CONR^(11b)—    -   (f) —CONR^(11a)—,    -   (g) —NR^(11a)CO—,    -   (h) —SO₂NR¹⁶—,    -   (i) —NR¹⁶SO₂—,    -   (j) —SO₂NR^(11a) SO₂—,    -   (k) —SO₂NR^(11a)CO₂—,    -   (l) —SO₂NR^(11a)CO₂—,    -   (m) —OCONR^(11a)SO₂—,    -   (n) —SO₂NR^(11a)CONR^(11b)—,    -   (o) —N^(R11a)CONR^(11b)SO₂—,    -   (p) —SO₂NR^(11a)SO₂—,    -   (q) —CONR^(11a)SO₂NR^(11b)—, or    -   (r) —NR^(11a)SO₂NR^(11b)CO—,

and pharmaceutically compatible salts of these compounds.

Illustrative of the compounds according to the specific embodimentsmentioned above are the following:

-   1-((2′-((i-Amyloxycarbonylamino)sulfonyl)-3-fluoro-(1,1′-biphenyl)-4-yl)methyl)-5-[2-(N-benzoyl-N-phenylamino)ethylcarbonyl]-4-ethyl-2-propyl-1H-imidazole,-   1-((2′-((n-Butyloxycarbonylamino)sulfonyl)-3-fluoro-(1,1′-biphenyl)-4-yl)methyl)-5-[2-(N-benzoyl-N-phenylamino)ethylcarbonyl]-4-ethyl-2-propyl-1H-imidazole,-   1-((2′-((n-Propyloxycarbonylamino)sulfonyl)-3-fluoro-(1,1′-biphenyl)-4-yl)methyl)-5-[2-(N-benzoyl-N-phenylamino)ethylcarbonyl]-4-ethyl-2-propyl-1,1-imidazole,-   1-((2′-((n-Butyloxycarbonylamino)sulfonyl)-3-fluoro-(1,1′-biphenyl)-4-yl)methyl)-5-[2-(N-benzoyl-N-butylamino)ethylcarbonyl]-4-ethyl-2-propyl-1H-imidazole,-   1-((2′-((n-Butyloxycarbonylamino)sulfonyl)-3-fluoro-(1,1′-biphenyl)-4-yl)methyl)-5-[2-(N-benzoyl-N-propylamino)ethylcarbonyl]-4-ethyl-2-propyl-1H-imidazole,-   1-((2′-((n-Butyloxycarbonylamino)sulfonyl)-3-fluoro-(1,1′-biphenyl)-4-yl)methyl)-5-[2-(N-butyryl-N-propylamino)ethylcarbonyl]-4-ethyl-2-propyl-1H-imidazole,-   1-((2′-((n-Butyloxycarbonylamino)sulfonyl)-3-fluoro-(1,1′-biphenyl)-4-yl)methyl)-5-[2-(N-butyryl-N-phenylamino)ethylcarbonyl]-4-ethyl-2-propyl-1H-imidazole,-   1-((2′-((i-Amyloxycarbonylamino)sulfonyl)-3-fluoro-(1,1′-biphenyl)-4-yl)methyl)-5-[2-(N-butyryl-N-phenylamino)ethylcarbonyl]-4-ethyl-2-propyl-1H-imidazole,-   1-((2′-((i-Amyloxycarbonylamino)sulfonyl)-3-fluoro-(1,1′-biphenyl)-4-yl)methyl)-5-[2-(N-isonicotinoyl-N-pyridin-3-ylamino)ethylcarbonyl]-4-ethyl-2-propyl-1H-imidazole,-   1-((2′-((n-Butyloxycarbonylamino)sulfonyl)-3-fluoro-(1,1′-biphenyl)-4-yl)methyl)-5-[2-(N-isonicotinoyl-N-pyridin-3-ylamino)ethylcarbonyl]-4-ethyl-2-propyl-1H-imidazole,-   1-((2′-((n-Butyloxycarbonylamino)sulfonyl)-3-fluoro-(1,1′-biphenyl)-4-yl)methyl)-5-[2-(N-nicotinoyl-N-pyridin-3-ylamino)ethylcarbonyl]-4-ethyl-2-propyl-1H-imidazole,-   1-((2′-((i-Amyloxycarbonylamino)sulfonyl)-3-fluoro-(1,1′-biphenyl)-4-yl)methyl)-5-[2-(N-nicotinoyl-N-pyridin-3-ylamino)ethylcarbonyl]-4-ethyl-2-propyl-1H-imidazole,-   1-((2′-((i-Amyloxycarbonylamino)sulfonyl)-3-fluoro-(1,1′-biphenyl)-4-yl)methyl)-5-[2-(N-nicotinoyl-N-pyridin-2-ylamino)ethylcarbonyl]-4-ethyl-2-propyl-1H-imidazole,-   1-((2′-((i-Amyloxycarbonylamino)sulfonyl)-3-fluoro-(1,1′-biphenyl)-4-yl)methyl)-5-[2-(N-isonicotinoyl-N-phenylamino)ethylcarbonyl]-4-ethyl-2-propyl-1H-imidazole,-   1-((2′-((i-Amyloxycarbonylamino)sulfonyl)-3-fluoro-(1,1′-biphenyl)-4-yl)methyl)-5-[2-(N-butyryl-N-pyridin-3-ylamino)ethylcarbonyl]-4-ethyl-2-propyl-1H-imidazole,-   1-((2′-((i-Amyloxycarbonylamino)sulfonyl)-3-fluoro-(1,1′-biphenyl)-4-yl)methyl)-5-[2-(N-isobutyryl-N-pyridin-3-ylamino)ethylcarbonyl]-4-ethyl-2-propyl-1H-imidazole,-   1-((2′-((n-Butyloxycarbonylamino)sulfonyl)-3-fluoro-(1,1′-biphenyl)-4-yl)methyl)-5-[2-(N-acetyl-N-pyridin-3-ylamino)ethylcarbonyl]-4-ethyl-2-propyl-1H-imidazole,-   1-((2′-((i-Amyloxycarbonylamino)sulfonyl)-3-fluoro-(1,1′-biphenyl)-4-yl)methyl)-5-[2-(N-butyryl-N-pyridin-2-ylamino)ethylcarbonyl]-4-ethyl-2-propyl-1H-imidazole-   1-((2′-((i-Amyloxycarbonylamino)sulfonyl)-(1,1′-biphenyl)-4-yl)methyl)-5-[2-(N-butyryl-N-pyridin-3-ylamino)ethylcarbonyl]-2-butyl-4-chloro-1H-imidazole,-   1-((2′-((i-amyloxycarbonylamino)sulfonyl)-3-fluoro-(1,1′-biphenyl)-4-yl)methyl)-5-[2-(N-propionyl-N-pyridin-3-ylamino)ethylcarbonyl]-4-ethyl-2-propyl-1H-imidazole,-   1-((2′-((i-Amyloxycarbonylamino)sulfonyl)(1,1′-biphenyl)-4-yl)methyl)-5-[2-(N-nicotinoyl-N-pyridin-3-ylamino)ethylcarbonyl]-4-ethyl-2-propyl-1H-imidazole,-   1-((2′-((i-Amyloxycarbonylamino)sulfonyl)(1,1′-biphenyl)-4-yl)methyl)-5-[2(N-butyryl-N-pyridin-3-ylamino)ethylcarbonyl]-4-ethyl-2-propyl-1H-imidazole,-   1-((2′-((n-Butyloxycarbonyl-amino)sulfonyl)-3-fluoro-(1,1′-biphenyl)-4-yl)methyl)-4-ethyl-5-(2-(2-phenoxyphenyl)ethylcarbonyl)-2-propyl-1H-imidazole,-   4-[((5-(2-Benzoylbenzyl    oxycarbonyl)-4-ethyl-2-n-propyl)imidazol-1-yl)methyl]-3-fluoro-2′-n-butyloxycarbonylaminosulfonyl-1,1′-biphenyl,-   4-[((5-(2-Benzoylbenzyloxycarbonyl)-4-ethyl-2-n-propyl)imidazol-1-yl)methyl]-3-fluoro-2′42-phenyl)ethyloxycarbonylaminosulfonyl)-1,1′-biphenyl,-   4-[((5-(2-Benzoylbenzyloxycarbonyl)-4-ethyl-2-n-propyl)imidazol-1-yl)methyl]-2′-((2-phenyl)ethyloxycarbonylaminosulfonyl)-1,1′-biphenyl,-   4-[((5-(2-Benzoylbenzyloxycarbonyl)-4-ethyl-2-n-propyl)imidazol-1-yl)methyl]-3-fluoro-2′-n-butyloxycarbonylaminosulfonyl-1,1′-biphenyl,-   4-[((5-(2-Benzoylbenzyloxycarbonyl)-4-ethyl-2-n-propyl)imidazol-1-yl)methyl]-3-fluoro-2′-n-isoamyloxycarbonylaminosulfonyl-1,1′-biphenyl,-   4-[((5-(2-Benzoylbenzyloxycarbonyl)-4-ethyl-2-n-propyl)imidazol-1-yl)methyl]-2′-n-isoamyloxycarbonylaminosulfonyl-1,1′-biphenyl,-   4-[((5-(2-Benzoylbenzyloxycarbonyl)-4-ethyl-2-n-propyl)imidazol-1-yl)methyl]-3-fluoro-2′-n-propyloxycarbonylaminosulfonyl-1,1′-biphenyl,-   4-[((5-(2-Isoamyloxybenzyloxycarbonyl)-4-ethyl-2-n-propyl)imidazol-1-yl)methyl]-3-fluoro-2′-n-butyloxycarbonylaminosulfonyl-1,1′-biphenyl,-   4-[((5-(2-Phenylaminocarbonyl)benzyloxycarbonyl-4-ethyl-2-n-propyl)imidazol-1-yl)methyl]-3-fluoro-2′-n-butyloxycarbonylaminosulfonyl-1,1′-biphenyl,-   4-[((5-(2-Benzoylbenzyloxycarbonyl)-4-ethyl-2-n-propyl)imidazol-1-yl)methyl]-3-fluoro-2′-(1H-tetrazol-5-yl)-1,1′-biphenyl,-   4-[((5-)2-trifluorophenyl)methylaminocarbonyl)-4-ethyl-2-n-propyl)imidazol-1-yl)methyl]-3-fluoro-2′-isoamyloxycarbonylaminosulfonyl-1,1′-biphenyl,-   N-butyl, N-benzyl-2-(aminocarbonyl)ethynylmethyl    4-ethyl-2-propyl-1-[[2′-(1H-tetrazol-5-yl)biphenyl-4-yl]methyl]imidazole-5-carboxylate,-   N,N-diphenyl-2-(aminocarbonyl)ethynylmethyl    4-ethyl-2-propyl-1-[[2′-(1H-tetrazol-5-yl)biphenyl-4-yl]methyl]imidazole-5-carboxylate,-   N-phenyl-2-(aminocarbonyl)ethyl-4-ethyl-2-propyl-1-[[2′-(1H-tetrazol-5-yl)biphenyl-4-yl]methyl]imidazole-5-carboxylate,-   N-butyl,    N-benzyl-4-(aminocarbonyl)propyl-4-ethyl-2-propyl-1-[[2′-(1H-tetrazol-5-yl)biphenyl-4-yl]methyl]imidazole-5-carboxylate,-   N,N-dipentyl-4-(aminocarbonyl)propyl    4-ethyl-2-propyl-1-[[2′-(tetrazol-5-yl)biphenyl-4-yl]methyl]imidazole-5-carboxylate,-   4-[(5-((2-benzoyl)phenylcarbonyloxymethyl)-4-chloro-2-n-propylimidazol-1-yl)methyl]-3-fluoro-2′-isoamyloxycarbonylaminosulfonylbiphenyl,-   1-((2′-((n-butyloxycarbonylamino)sulfonyl)-3-fluoro-(1,1′-biphenyl)-4-yl)methyl)-2-(n-propyl)-4-ethyl-5-(2-(phenoxy)phenoxy)acetyl-1H-imidazole,

In the embodiments described above for compounds according to formulae(IVa)-(VIa), when an alkyl substituent is mentioned, the normal alkylstructure is meant (e.g. butyl is n-butyl) unless otherwise specified.However, in the definition of radicals above (e.g. R³), both branchedand straight chains are included in the scope of alkyl, alkenyl andalkynyl.

In the embodiments described above for compounds according to formulae(IVa)-(VIa), the term “aryl” is meant to include phenyl, biphenyl,napthyl, or fluorenyl group optionally substituted with one to threesubstituents selected from the group consisting of —OH, —SH,C₁-C₄-alkyl, C₁-C₄-alkoxy, —CF₃, halo, —NO₂, —CO₂H, —CO₂CH₃,—CO₂-benzyl, —NH.sub.2, —NH(C₁-C₄-alkyl), —N(C₁-C₄-alkyl)₂. The termheteroaryl is meant to include unsubstituted, monosubstituted ordisubstituted 5- to 10-membered mono- or bicyclic aromatic rings whichcan optionally contain from 1 to 3 heteroatoms selected from the groupconsisting of O, N, and S. Included in the definition of the groupheteroaryl, but not limited to, are the following: pyridyl, pyridazinyl,pyrimidinyl, pyrazinyl, 1,3,5-triazinyl, furyl, thiophenyl, imidazolyl,oxazolyl, thiazolyl, benzofuranyl, benzothiophenyl, benzimidazolyl,benzoxazolyl, benzothiazolyl, indolin-2-onyl, indolinyl, indolyl,pyrrolyl, quinonlinyl and isoquinolinyl. Particularly preferred are 2-,3-, or 4-pyridyl; 2-, or 3-furyl; 2-, or 3-thiophenyl; 2-, 3-, or4-quinolinyl; or 1-, 3-, or 4-isoquinolinyl optionally substituted withone to three substituents selected from the group consisting of —OH,—SH, C₁-C₄-alkyl, C₁-C₄-alkoxy, —CF₃, halo, NO₂, —CO₂H, —CO₂CH₃,—CO₂-benzyl, —NH₂, —NH(C₁-C₄alkyl), —N(C₁-C₄-alkyl)₂. The term aryleneis meant to include a phenyl, biphenyl, napthyl, or fluorenyl groupwhich is used as a link for two groups to form a chain. Included in thedefinition of arylene, but not limited to, are the following isomericlinkers: 1,2-phenyl, 1,3-phenyl, 1,4-phenyl; 4,4′-biphenyl,4,3′-biphenyl, 4,2′-biphenyl, 2,4′-biphenyl, 2,3′-biphenyl,2,2′-biphenyl, 3,4′-biphenyl, 3,3′-biphenyl, 3,2′-biphenyl, 1,2-napthyl,1,3-napthyl, 1,4-napthyl, 1,5-napthyl, 1,6-napthyl, 1,7-napthyl,1,8-napthyl, 2,6-napthyl, 2,3-napthyl; 1,4-fluorenyl. Particularlypreferred are 1,2-phenyl, 1,3-phenyl, 1,4-phenyl, 4,4′-biphenyl,3,3′-biphenyl, and 2,2′-biphenyl optionally substituted with one tothree substituents selected from the group consisting of —OH, —SH,C₁-C₄-alkyl, —CF₃, halo, —NO₂, —CO₂H, —CO₂CH₃, —CO₂-benzyl, —NH₂,—NH(C₁-C₄-alkyl), —N(C₁-C₄-alkyl)₂.

In the embodiments described above for compounds according to formulae(IVa)-(VIa), the term heteroarylene is meant to include unsubstituted 5-to 10-membered aromatic ring which can optionally contain from 1 to 3heteroatoms selected from the group consisting of O, N, and S which isused as a link for two groups to form a chain. Included in thedefinition of the group heteroaryl, but not limited to, are thefollowing: 2,3-pyridyl, 2,4-pyridyl, 2,5-pyridyl, 2,6-pyridyl,3,4-pyridyl, 3,5-pyridyl, 3,6-pyridyl; 2,3-furyl, 2,4-furyl, 2,5-furyl;2,3-thiophenyl, 2,4-thiophenyl, 2,5-thiophenyl; 4,5-imidazolyl,4,5-oxazolyl; 4,5-thiazolyl; 2,3-benzofuranyl; 2,3-benzothiophenyl;2,3-benzimidazolyl; 2,3-benzoxazolyl; 2,3-benzothiazolyl;3,4-indolin-2-onyl; 2,4-indolinyl; 2,4-indolyl; 2,4-pyrrolyl;2,4-quinolinyl, 2,5-quinolinyl, 4,6-quinolinyl; 3,4-isoquinolinyl,1,5-isoquinolinyl. Particularly preferred are 2,3-pyridyl, 3,4-pyridyl,2,3-furyl, 3,4-furyl 2,3-thiophenyl, 3,4-thiophenyl, 2,3-quinolinyl,3,4-quinolinyl and 1,4-isoquinolinyl optionally substituted with one tothree substituents selected from the group consisting of —OH, —SH,C₁-C₄-alkyl, C₁-C₄-alkoxy, —CF₃, halo, —NO₂, —CO₂H, —CO₂CH₃,—CO₂-benzyl, —NH₂, —NH(C₁-C₄alkyl), —N(C₁-C₄-alkyl)₂;

It should be noted in the foregoing structural formula, when a radicalcan be a substituent in more than one previously defined radical, thatfirst radical (R¹¹, B or y) can be selected independently in eachpreviously defined radical. For example, R¹ and R² can each be—CONHOR¹². R¹² need not be the same substituent in each of R¹ and R²,but can be selected independently for each of them. Or if, for example,the same R group (let us take R², for instance) appears twice in amolecule, each of those R groups is independent of each other (one R²group may be —CONHOR¹², while the other R² group may be —CN).

In still other embodiments, the AT₂ receptor antagonist is selected fromthe compounds listed in U.S. Pat. No. 5,338,740 and especially in thecompound claims of this patent, which a heterocyclic ring (hereafterreferred to as “Het”) is connected to an aryl or thienyl group(hereafter referred to as “Ar”) via a carbobicyclic or heterobicyclicspacer group (hereafter referred to as “W”). Representative examples ofsuch compounds are represented by the formula (VIIa):

Ar-W-Het  (VIIa)

wherein:

-   -   Ar is selected from the group consisting of

-   -   and X¹, X², X³ and X⁴ are independently selected from CR² and        nitrogen;    -   one of X⁵ and X⁶ is CH and the other is S;    -   R¹ is selected from the group consisting of CO₂H, —NHSO₂CF₃,        —CONHSO₂—(C₁-C₈)alkyl, PO₃H₂, SO₃H, —CONHSO₂(C₆H₅), —CONHSO₂CF₃,        tetrazole,

-   -   and —SO₂NHCO₂—(C₁-C₈)alkyl;    -   R² is selected from hydrogen, (C₁-C₈)alkyl, (C₂-C₁₀)alkenyl,        (C₃-C₈)cycloalkyl, halo, hydroxy, —O—(C₁-C₆)alkyl,        —S—(C₁-C₆)alkyl, —SO—(C₁-C₆)alkyl —SO₂—(C₁-C₆)alkyl, —NR³R⁴, and        phenyl, wherein said phenyl is optionally mono-, di- or        tri-substituted with substituents independently selected from        hydrogen, (C₁-C₈)alkyl, (C₂-C₁₀)alkenyl, (C₃-C₈)cycloalkyl,        halo, (C₁-C₆)alkoxy, —S—(C₁-C₆)alkyl, —SO—C₁-C₆)alkyl,        —SO₂—(C₁-C₆)alkyl, —O—(C₁-C₆)alkyl, and —NR⁴R⁴;

R³ and R⁴ are independently selected from hydrogen, (C₁-C₈)alkyl,(C₂-C₁₀)alkenyl and (C₁-C₈)cycloalkyl, or R³ and R⁴, together with thenitrogen to which they are attached, form a cyclic 5-7 memberedsaturated or partially saturated carbocyclic or heterocyclic ring withone or two heteroatoms independently selected from nitrogen, oxygen andsulfur; and the dotted line represents that the ring containing X⁵ andX⁶ is aromatic:

-   -   W is a carbobicyclic or heterobicyclic ring system having the        formula:

-   -   and X⁸, X⁹, X¹⁰ and X¹¹ are present or absent, and each of X⁷,        X⁸, X⁹, X¹⁰ and X¹¹ is independently selected from CHR⁵, O, S,        SO, SO², and NR^(S);    -   X¹², X¹³, and X¹⁴ are independently selected from CR⁷ or N;    -   X¹⁵ and X¹⁶ are independently selected from CR⁷ and S;    -   R⁵ is absent when the CH moiety of CHR⁵ is connected to Het and        when

R⁵ is present it is selected from hydrogen, (C₁-C₈)alkyl,(C₂-C₁₀)alkenyl, (C₃-C₈)cycloalkyl, —O—(C₁-C₆)alkyl, and phenyl, whereinsaid phenyl is optionally mono-, di- or tri-substituted withsubstituents independently selected from hydrogen, (C₁-C₈)alkyl,(C₂-C₁₀)alkenyl, (C₃-C₈)cycloalkyl, halo, (C₁-C₆)alkoxy,—S—(C₁-C₆)alkyl, —SO—(C₁-C₆)alkyl, —SO₂—(C₁-C₆)alkyl, —O—(C₁-C₆)alkyl,and —NR³, R⁴;

R⁶ is selected from (C₁-C₈)alkyl, (C₃-C₈)cycloalkyl and phenyl, whereinsaid cycloalkyl is saturated or partially saturated and wherein saidcycloalkyl may optionally contain a heteroatom selected from nitrogen,oxygen, and sulfur, and said phenyl is optionally mono-, di- ortri-substituted with substituents independently selected from hydrogen,(C₁-C₈)alkyl, (C₁-C₁₀)alkenyl, (C₃-C₈)cycloalkyl, halo, (C₁-C₆)alkoxy,—S—(C₁-C₆)alkyl, —SO—(C₁-C₆)alkyl, —SO₂—(C₁-C₆)alkyl, —O—(C₁-C₆)alkyl,and —NR³R⁴;

R⁷ is selected from hydrogen, (C₁-C₈)alkyl, (C₂-C₁₀)alkenyl,(C₃-C₈)cycloalkyl, halo, hydroxy, —O—(C₁-C₆)alkyl, —S—(C₁-C₆)alkyl,—SO—(C₁-C₆)alkyl, —SO₂-(C₁-C₆)alkyl, —NR³R⁴, and phenyl, wherein saidphenyl is optionally mono-, di- or tri-substituted with substituentsselected from hydrogen, (C₁-C₈)alkyl, (C₁-C₁₀)alkenyl,(C₃-C₈)cycloalkyl, halo, (C₁-C₆)alkoxy, —S—(C₁-C₆)alkyl,—SO—(C₁-C₆)alkyl, —SO₂—(C₁-C₆)alkyl, —O—(C₁-C₆)alkyl, and —NR³R⁴;

-   -   and the dotted line represents that the ring containing X¹⁵ and        X¹⁶ contain one or two double bonds; and    -   Het is selected from the group consisting of:

-   -   and R⁸, R⁹, R¹⁰ and R¹¹ are independently selected from        hydrogen, (C₁-C₈)alkyl, (C₁-C₁₀)alkenyl, (C₃-C₈)cycloalkyl,        halo, (C₁-C₈)alkoxy, —S—(C₁-C₆)alkyl, —SO—(C₁-C₆)alkyl, —CO₂H,        —SO₂NR₃R₄, —NR₃R₄, and phenyl, wherein said phenyl is optionally        mono-, di-, or tri-substituted with halo, hydroxy, nitro,        (C₁-C₈)alkyl, (C₃-C₆)cycloalkyl, (C₁-C₇)alkoxy,        (C₁-C₇)alkylthio, and amino, wherein said amino is optionally        mono- or di-substituted with (C₁-C₇)alkyl;    -   and wherein each occurrence of R³ can be the same or different        from any other occurrence of R³, and each occurrence of R⁴ can        be the same or different from any other occurrence of R⁴;    -   with the proviso that: (a) no more than two of X¹, X², X³ and X⁴        can be nitrogen; and (b) at least two of X⁷, X⁸, X⁹, X¹⁰ and X¹¹        are present;

and to pharmaceutically compatible salts thereof.

As used herein for compounds according to formula (VIIa):

the term “halo,” unless otherwise indicated, includes chloro, fluoro,bromo and iodo;

the term “alkyl”, unless otherwise indicated, includes saturatedmonovalent hydrocarbon radicals having straight, branched or cyclicmoieties or combinations thereof, for example methyl, ethyl, n-propyl,isopropyl, n-butyl, isobutyl and t-butyl;

the term “alkenyl,” unless otherwise indicated, means straight orbranched unsaturated hydrocarbon radicals, for example, ethenyl, 1- or2-propenyl, 2-methyl-1-propenyl and 1- or 2-butenyl;

the term “cycloalkyl,” unless otherwise indicated, means a saturatedcarbocyclic radical, for example, cyclopropyl, cyclobutyl, cyclopentyland cyclohexyl; and the term “alkoxy”, unless otherwise indicated,includes O-alkyl groups wherein “alkyl” is defined as above.

In specific embodiments, compounds according to formula (VIIa) includethose wherein W has the formula

Examples of specific preferred compounds according to formula (VIIa)are:

-   2-butyl-5-chloro-1-{5-[2-(1H-tetrazol-5-yl)-phenyl]-indan-1-yl}-1H-imidazole-4-carboxylic    acid ethyl ester;-   2-butyl-5-chloro-1-{5-[2-(1H-tetrazol-5-yl)-phenyl]-indan-1-yl}-1H-imidazole-4-carboxylic    acid;-   2-butyl-3-{5-[2-(1H-tetrazol-5-yl)-phenyl]-indan-1-yl}-1,3-diazaspiro[4.4]non-1-en-4-one;-   (2-butyl-5-chloro-1-{5-[2-(1H-tetrazol-5-yl)-phenyl]-indan-1-yl}-1H-imidazol-4-yl)methanol-   2-ethyl-5,7-dimethyl-3-{5-[2-(1H-tetrazol-5-yl)-phenyl]-indan-1-yl}-3H-imidazole[4,5-b]pyridine;-   (S)-2-ethyl-5,7-dimethyl-3-{5-[2-(1H-tetrazol-5-yl)-phenyl]-indan-1-yl}-3H-imidazo[4,5-b]pyridine;-   (R)-2-ethyl-5,7-dimethyl-3-{5-[2-(1H-tetrazol-5-yl)-phenyl]-indan-1-yl}-3H-imidazol[4,5-b]pyridine;-   2-ethyl-7-methyl-3-{5-[2-(1H-tetrazol-5-yl)-phenyl}-indan-1-yl}-3H-imidazo[4,5-b]pyridine;-   5,7-dimethyl-2-propyl-3-{5-[2-(1H-tetrazol-5-yl)-phenyl]-indan-1-yl}-3H-imidazo[4,5-b]pyridine;-   2-cyclopropyl-5,7-dimethyl-3-{5-[2-(1H-tetrazol-5-yl)-phenyl]-indan-1-yl}-3H-imidazo[4,5-b]pyridine;-   2-butyl-5,7-dimethyl-3-{5-[2-(1H-tetrazol-5-yl)-phenyl]-indan-1-yl}-3H-imidazo[4,5-b]pyridine;-   2-butyl-3-{5-[2-(1H-tetrazol-5-yl)-phenyl]-indan-1-yl}-3H-imidazo[4,5-b]pyridine;-   2-[1-(2-ethyl-5,7-dimethyl-imidazo[4,5-b]pyridin-3-yl)-indan-5-yl-benzoic    acid;-   2-[5-(2-ethyl-5,7-dimethyl-imidazo[4,5-b]pyridin-3-yl)-5,6,7,8-tetrahydro-4H-naphthalen-2-yl]-benzoic    acid;-   2-ethyl-5,7-dimethyl-3-{6-[2-(1H-tetrazol-5-yl)-phenyl]-1,2,3,4-tetrahydro-4H-naphthalen-1-yl}-3H-imidazo[4,5-b]pyridine;-   2-ethyl-5,7-dimethyl-3-{2-[2-(1H-tetrazol-5-yl)-phenyl]-6,7,8,9-tetrahydro-5H-benzocyclohepten-5-yl}-3H-imidazo[4,5-b]pyridine;-   2-ethyl-5,7-dimethyl-3-{7-[2-(1H-tetrazol-5-yl)-phenyl]-chroman-4-yl}-3H-imidazo[4,5-b]pyridine;-   2-ethyl-5,7-dimethyl-3-{3-[2-(1H-tetrazol-5-yl)-phenyl]-bicyclo[4.2.0]octa-1,3,5-trien-7-yl}-3H-imidazo[4,5-b]pyridine;-   2-ethyl-5,7-dimethyl-3-{7-[2-(1H-tetrazol-5-yl)-phenyl]-chroman-4-yl}-3H-imidazo[4,5-b]pyridine;-   2-ethyl-5,7-dimethyl-3-{3-[2-(1H-tetrazol-5-yl)-phenyl]-6,7-dihydro-5H-[1]pyridin-7-yl}-3H-imidazo[4,5-b]pyridine;-   2-[5-(2-butyl-imidazo[4,5-b]pyridin-3-yl)-naphthalen-2-yl]-benzoic    acid;-   2-butyl-3-{6-[2-(1H-tetrazol-5-yl)-phenyl]-naphthalen-1-yl}3H-imidazo[4,5-b]pyridine;    and-   2-ethyl-5,7-dimethyl-3-{6-[2-(1H-tetrazol-5-yl)-phenyl-naphthalen-1-yl}-3    H-imidazo[4,5-b]pyridine.

Other compounds of according to formula (VIIa) include the following:

-   2-ethyl-5,7-dimethyl-3-{7-[2-(2H-tetrazol-5-yl)-phenyl]-thiochroman-4-yl}-3    H-imidazo[4,5-b]pyridine;-   3-{1,1-dioxo-7-[2-(2H-tetrazol-5-yl)-phenyl]-thiochroman-4-yl}-2-ethyl-5,7-dimethyl-3H-imidazo[4,5-b]pyridine;-   2-ethyl-5,7-dimethyl-3-{2-[2-(2H-tetrazol-5-yl)-phenyl]-5,6-dihydro-4H-thieno[2,3-b]thiopyran-4-yl}-3H-imidazo[4,5-b]pyridine;-   2-ethyl-5,7-dimethyl-3-{2-[2-(2H-tetrazol-5-yl)-phenyl]-4,5,6,7-tetrahydrobenzo[b]thiophen-4-yl}-3H-imidazo[4,5-b]pyridine;    P0    2-ethyl-5,7-dimethyl-3-{2-[2-(2H-tetrazol-5-yl)-phenyl]-5,6-dihydro-4H-cyclopenta[b]thiophen-4-yl}-3H-imidazo[4,5-b]pyridine;-   2-ethyl-5,7-dimethyl-3-{6-[2-(2H-tetrazol-5-yl)-phenyl]-3,4-dihydro-2H-thieno[2,3-b]pyran-4-yl}-3H-imidazo[4,5-b]pyridine;-   2-ethyl-5,7-dimethyl-3-{2-[2-(2H-tetrazol-5-yl)-phenyl]-6,7-dihydro-5H-[1]pyridin-5-yl}-3H-imidazo[4,5-b]pyridine;-   5-(2-ethyl-5,7-dimethyl-imidazo[4,5-b]pyridin-3-yl)-2-[2-(2H-tetrazol-5-yl)-phenyl]-5,6,7,8-tetrahydro-quinoline;-   4-(2ethyl-5,7-dimethyl-imidazo[4,5-b]pyridin-3-yl)-7-[2-(2H-tetrazol-5-yl)-phenyl]-3,4-dihydro-2H-thiopyrano[2,3-b]pyridine-1,1-dioxide;-   2-ethyl-5,7-dimethyl-3-{2-[2-(2H-tetrazol-5-yl)-phenyl]-6,7-dihydro-5H-cyclopentapyrimidin-5-yl}-3H-imidazo[4,5-b]pyridine;-   2-ethyl-5,7-dimethyl-3-{3-[2-(2H-tetrazol-5-yl)-phenyl]-6,7-dihydro-5H-[2]pyrindin-7-yl}-3H-imidazo[4,5-b]pyridine;-   2-ethyl-5,7-dimethyl-3-{5-[3-(2H-tetrazol-5-yl)-thiophen-2-yl]-indan-1-yl}-3H-imidazo[4,5-b]pyridine;-   2-ethyl-5,7-dimethyl-3-{5-[2-(2H-tetrazol-5-yl)-thiophen-3-yl]-indan-1-yl}-3H-imidazo[4,5-b]pyridine;-   2-ethyl-5,7-dimethyl-3-{5-[4-(2H-tetrazol-5-yl)-thiophen-3-yl]-indan-1-yl}-3H-imidazo[4,5-b]pyridine;-   2-ethyl-5,7-dimethyl-3-{5-[3-(2H-tetrazol-5-yl)-pyridin-4-yl]-indan-1-yl}-3H-imidazo[4,5-b]pyridine;-   2-ethyl-5,7-dimethyl-3-{5-[4-(2H-tetrazol-5-yl)-pyridin-3-yl]-indan-1-yl}-3H-imidazo[4,5-b]pyridine;-   2-ethyl-5,7-dimethyl-3-{5-[3-(2H-tetrazol-5-yl)-pyridin-2-yl]-indan-1-yl}-3H-imidazo[4,5-b]pyridine;-   (2-butyl-5-chloro-3-{5-[2-(2H-tetrazol-5-yl)-phenyl]-indan-1-yl}-3H-imidazole-4-yl)methanol;-   2-butyl-5-chloro-3-{5-[2-(2H-tetrazol-5-yl)-phenyl]-indan-1-yl}-3H-imidazole-4-carboxylic    acid;-   2-butyl-5-(1,1,2,2,2-pentafluoro-ethyl)-3-{5-[2-(2H-tetrazol-5-yl)-phenyl]-indan-1-yl}-3H-imidazole-4-carboxylic    acid;-   2-butyl-5-ethyl-3-{5-[2-(2H-tetrazol-5-yl)-phenyl]-indan-1-yl}-3H-imidazole-4-carboxylic    acid;-   2-ethoxy-3-{5-[2-(2H-tetrazol-5-yl)-phenyl]-indan-1-yl}-3H-benzoimidazole-4-carboxylic    acid;-   2-ethylsulfanyl-3-{5-[2-(2H-tetrazol-5-yl)-phenyl]-indan-1-yl}-3H-benzoimidazole-4-carboxylic    acid;-   N-benzoyl-2-[1-(2-ethyl-5,7-dimethyl-imidazo[4,5-b]pyridin-3-yl)-indan-5-yl]-benzenesulfonamide;    and-   N-{2-[1-(2-ethyl-5,7-dimethyl-imidazo[4,5-b]pyridin-3-yl)-indan-5-yl]-phenyl}-benzenesulfonamide.

In further embodiments, the AT₂ receptor antagonist is selected from AT₂receptor antagonist peptides, illustrative examples of which includehexa-, hepta- and octapeptides represented by the formula:

R₁—R₂-R₃—R₄-R₅—R₆-Pro-R₇  (VIII)

wherein:

R₁ is absent or is selected from hydrogen, succinyl, L-aspartyl,sarcosyl, L-seryl, succinamyl, L-propyl, glycyl, L-tyrosyl,N_(α)-nicotinoyl-tyrosyl, or D- or L-asparagyl;

-   -   R₂ is selected from arginyl or N-benzoylcarbonyl arginyl;    -   R₃ is absent or valyl;    -   R₄ is absent or is selected from L-phenylalanyl or L-tyrosyl;    -   R₅ is selected from valyl, L-isoleucyl, L-alanyl or L-lysyl;    -   R₆ is selected from L-histidyl, L-isoleucyl, L-tyrosyl or        p-aminophenylalanyl; and    -   R₇ is selected from L-alanine, L-tyrosine, L- or D-leucine,        glycine, L-isoleucine or β-alanine residue.

and pharmaceutically acceptable salts of these peptides.

Representative examples according to formula (VIII) include, but are notlimited to:

[SEQ ID NO: 1] H-Asn-Arg-Val-Tyr-Val-His-Pro-Ala-OH; [SEQ ID NO: 2]H-Asn-Arg-Val-Tyr-Val-His-Pro-Leu-OH; [SEQ ID NO: 3]Succinyl-Arg-Val-Tyr-Val-His-Pro-Ala-OH; [SEQ ID NO: 4]H-Asp-Arg-Val-Tyr-Val-His-Pro-Ala-OH; [SEQ ID NO: 5]H-Arg-Val-Tyr-Val-His-Pro-Ala-OH; [SEQ ID NO: 6]H-Sar-Arg-Val-Tyr-His-Pro-Ala-OH; [SEQ ID NO: 7]H-Ser-Arg-Val-Tyr-His-Pro-Ala-OH; [SEQ ID NO: 8]Succinamyl-Arg-Val-Tyr-Val-His-Pro-Ala-OH; [SEQ ID NO: 9]H-Asn-Arg-Val-Tyr-Val-His-Pro-Gly-OH; [SEQ ID NO: 10]H-Asn-Arg-Val-Tyr-Val-His-Pro-Ile-OH; [SEQ ID NO: 11]H-Sar-Arg-Val-Tyr-Val-His-Pro-Gly-OH; [SEQ ID NO: 12]H-Pro-Arg-Val-Tyr-Val-His-Pro-Gly-OH; [SEQ ID NO: 13]H-Asn-Arg-Val-Tyr-Val-His-Pro-Gly-OH; [SEQ ID NO: 14]H-Sar-Arg-Val-Tyr-Val-His-Pro-β-Ala-OH; [SEQ ID NO: 15]H-Asn-Arg-Val-Tyr-Val-His-Pro-β-Ala-OH; [SEQ ID NO: 16]H-Gly-Arg-Val-Tyr-Val-His-Pro-Ala-OH; [SEQ ID NO: 17]H-Sar-Arg-Val-Tyr-Ile-His-Pro-Leu-OH; [SEQ ID NO: 18]H-Asn-Arg-Val-Tyr-Val-His-Pro-Leu-OH; [SEQ ID NO: 19]H-Sar-Arg-Val-Tyr-Ile-His-Pro-Ala-OH, also known as saralasin;[SEQ ID NO: 20] H-Asn-Arg-Val-Tyr-Ile-His-Pro-Ala-OH; [SEQ ID NO: 21]H-Asn-Arg-Val-Tyr-Ala-His-Pro-Ala-OH; [SEQ ID NO: 22]H-Asp-Arg-Val-Phe-Ile-His-Pro-Tyr-OH, also known as Phe⁴-Tyr⁸-Ang II;[SEQ ID NO: 23] H-Asp-Arg-Val-Tyr-Ile-p-NH₂Phe-Pro-Phe-OH, alsoknown as [p-NH₂Phe]⁶-Ang II; and [SEQ ID NO: 24]nicotinic acid-Tyr-(N-benzoylcarbonyl-Arg)-Lys-His-Pro-Ile-OH, also known as CGP-42112A;

In other embodiments, the AT₂ receptor antagonist is selected fromantigen-binding molecules that are immuno-interactive with an AT₂receptor polypeptide. Illustrative antigen-binding molecules includewhole polyclonal antibodies. Such antibodies may be prepared, forexample, by injecting an AT₂ receptor polypeptide or fragment thereofinto a production species, which may include mice or rabbits, to obtainpolyclonal antisera. Methods of producing polyclonal antibodies are wellknown to those skilled in the art. Exemplary protocols which may be usedare described for example in Coligan et al., “Current Protocols InImmunology”, (John Wiley & Sons, Inc, 1991), and Ausubel et al.,(Current Protocols in Molecular Biology”, John Wiley & Sons Inc,1994-1998), in particular Section III of Chapter 11.

In lieu of the polyclonal antisera obtained in the production species,monoclonal antibodies may be produced using the standard method asdescribed, for example, by Köhler and Milstein (1975, Nature 256,495-497), or by more recent modifications thereof as described, forexample, in Coligan et al., (1991, supra) by immortalizing spleen orother antibody-producing cells derived from a production species whichhas been inoculated with an AT₂ receptor polypeptide or fragmentthereof.

The invention also contemplates as antigen-binding molecules Fv, Fab,Fab′ and F(ab′)₂ immunoglobulin fragments. Alternatively, theantigen-binding molecule may be in the form of a synthetic stabilized Fvfragment, a single variable region domain (also known as a dAbs), a“minibody” and the like as known in the art.

Also contemplated as antigen binding molecules are humanized antibodies.Humanized antibodies are produced by transferring complementarydetermining regions from heavy and light variable chains of a non human(e.g., rodent, preferably mouse) immunoglobulin into a human variabledomain. Typical residues of human antibodies are then substituted in theframework regions of the non human counterparts. The use of antibodycomponents derived from humanized antibodies obviates potential problemsassociated with the immunogenicity of non human constant regions.General techniques for cloning non human, particularly murine,immunoglobulin variable domains are described, for example, by Orlandiet al. (1989, Proc. Natl. Acad. Sci. USA 86: 3833). Techniques forproducing humanized monoclonal antibodies are described, for example, byJones et al. (1986, Nature 321:522), Carter et al. (1992, Proc. Natl.Acad. Sci. USA 89: 4285), Sandhu (1992, Crit. Rev. Biotech. 12: 437),Singer et al. (1993, J. Immun. 150: 2844), Sudhir (ed., AntibodyEngineering Protocols, Humana Press, Inc. 1995), Kelley (“EngineeringTherapeutic Antibodies,” in Protein Engineering: Principles and PracticeCleland et al. (eds.), pages 399-434 (John Wiley & Sons, Inc. 1996), andby Queen et al., U.S. Pat. No. 5,693,762 (1997).

Illustrative antigen-binding molecules that are immuno-interactive withAT₂ receptor polypeptides and methods for their preparation aredescribed by Nora et al. (1998, Am J Physiol. 275(4 Pt 2):H1395-403),Yiu et al. (1997, Regul Pept. 70(1):15-21), Reagan et al. (1993, ProcNatl Acad Sci USA. 90(17):7956-7960), Rakugi et al. (1997, HypertensRes. 20(1):51-55) and Wang et al. (1998 Hypertension. 32(1):78-83), andsome are available commercially, such as but not limited to H-143 (SantaCruz Biotechnology, Santa Cruz, Calif.), which is directed against aminoacid residues 221-363 from the carboxy terminus of human AT₂, rAT2 (Ab#1), which is directed against an 18-residue C-terminal fragment of ratAT₂), rAT2 (Ab #2) which is directed against an 18-residue C-terminalfragment of rat AT₂) and rAT2 (Ab #3), which is directed against a10-residue N-terminal fragment of rat AT₂ (Alpha DiagnosticInternational, Inc.—5415 Lost Lane, SA).

In still other embodiments, the AT₂ receptor antagonist is selected fromnucleic acid molecules that inhibit or otherwise reduce the level orfunctional activity of an expression product of an AT₂ gene,illustrative examples of which include antisense molecules, ribozymesand RNAi molecules. Thus, the present invention contemplates antisenseRNA and DNA molecules as well as ribozymes and RNAi molecules thatfunction to inhibit the translation, for example, of Agtr2 mRNA.Antisense RNA and DNA molecules act to directly block the translation ofmRNA by binding to targeted mRNA and preventing protein translation. Inregard to antisense DNA, oligodeoxyribonucleotides derived from thetranslation initiation site, e.g., between −10 and +10 regions of anAgtr2 gene, are desirable. Exemplary antisense oligonucleotides can bederived from any nucleic acid molecule that encodes an AT₂ receptor,such as those described in U.S. Pat. No. 5,556,780, and in U.S. Pat.Appl. Pub. No. 20030083339. Therapeutic methods utilizing antisenseoligonucleotides have been described in the art, for example, in U.S.Pat. Nos. 5,627,158 and 5,734,033. Generally, antisense moleculescomprise from about 8 to about 30 bases (i.e., from about 8 to about 30linked nucleosides) and typically comprise from about 12 to about 25bases.

Ribozymes are enzymatic RNA molecules capable of catalyzing the specificcleavage of RNA. The mechanism of ribozyme action involves sequencespecific hybridization of the ribozyme molecule to complementary targetRNA, followed by an endonucleolytic cleavage. Within the scope of theinvention are engineered hammerhead motif ribozyme molecules thatspecifically and efficiently catalyze endonucleolytic cleavage of Agtr2RNA sequences. Specific ribozyme cleavage sites within any potential RNAtarget are initially identified by scanning the target molecule forribozyme cleavage sites which include the following sequences, GUA, GUUand GUC. Once identified, short RNA sequences of between 15 and 20ribonucleotides corresponding to the region of the target genecontaining the cleavage site may be evaluated for predicted structuralfeatures such as secondary structure that may render the oligonucleotidesequence unsuitable. The suitability of candidate targets may also beevaluated by testing their accessibility to hybridization withcomplementary oligonucleotides, using ribonuclease protection assays.

Both antisense RNA and DNA molecules and ribozymes may be prepared byany method known in the art for the synthesis of nucleic acid molecules.These include techniques for chemically synthesizingoligodeoxyribonucleotides well known in the art such as for examplesolid phase phosphoramidite chemical synthesis. Alternatively, RNAmolecules may be generated by in vitro and in vivo transcription of DNAsequences encoding the antisense RNA molecule. Such DNA sequences may beincorporated into a wide variety of vectors which incorporate suitableRNA polymerase promoters such as the T7 or SP6 polymerase promoters.Alternatively, antisense cDNA constructs that synthesize antisense RNAconstitutively or inducibly, depending on the promoter used, can beintroduced stably into cell lines.

Various modifications to nucleic acid molecules may be introduced as ameans of increasing intracellular stability and half-life. Possiblemodifications include but are not limited to the addition of flankingsequences of ribo- or deoxy-nucleotides to the 5′ and/or 3′ ends of themolecule or the use of artificial linkages rather than phosphodiesteraselinkages within the oligodeoxyribonucleotide backbone. Illustrativemodified oligonucleotide backbones include, for example,phosphorothioates, chiral phosphorothioates, phosphorodithioates,phosphotriesters, aminoalkylphosphotriesters, methyl and other alkylphosphonates including 3′-alkylene phosphonates and chiral phosphonates,phosphinates, phosphoramidates including 3′-amino phosphoramidate andaminoalkylphosphoramidates, thionophosphoramidates,thionoalkylphosphonates, thionoalkylphosphotriesters, andboranophosphates having normal 3′-5′ linkages, 2′-5′ linked analogs ofthese, and those having inverted polarity wherein the adjacent pairs ofnucleoside units are linked 3′-5′ to 5′-3′ or 2′-5′ to 5′-2′. Varioussalts, mixed salts and free acid forms are also included.

Other agents that may be used to decrease the expression of an Agtr2gene or the level and/or functional activity of an expression product ofthat gene include RNA molecules that mediate RNA interference (RNAi) ofa Agtr2 gene or gene transcript. RNAi refers to interference with ordestruction of the product of a target gene by introducing a singlestranded, and typically a double stranded RNA (dsRNA), which ishomologous to the transcript of the target gene. Thus, in oneembodiment, dsRNA per se and especially dsRNA-producing constructs thatencode an amino acid sequence corresponding to at least a portion of anAT₂ receptor polypeptide may be used to decrease its level and/orfunctional activity. RNAi-mediated inhibition of gene expression may beaccomplished using any of the techniques reported in the art, forinstance by transfecting a nucleic acid construct encoding a stem-loopor hairpin RNA structure into the genome of the target cell, or byexpressing a transfected nucleic acid construct having homology for atarget gene from between convergent promoters, or as a head to head ortail to tail duplication from behind a single promoter. Any similarconstruct may be used so long as it produces a single RNA having theability to fold back on itself and produce a dsRNA, or so long as itproduces two separate RNA transcripts which then anneal to form a dsRNAhaving homology to a target gene.

Absolute homology is not required for RNAi, with a lower threshold beingdescribed at about 85% homology for a dsRNA of about 200 base pairs(Plasterk and Ketting, 2000, Current Opinion in Genetics and Dev. 10:562-567). Therefore, depending on the length of the dsRNA, theRNAi-encoding nucleic acids can vary in the level of homology theycontain toward the target gene transcript, i.e., with dsRNAs of 100 to200 base pairs having at least about 85% homology with the target gene,and longer dsRNAs, i.e., 300 to 100 base pairs, having at least about75% homology to the target gene. RNA-encoding constructs that express asingle RNA transcript designed to anneal to a separately expressed RNA,or single constructs expressing separate transcripts from convergentpromoters, are preferably at least about 100 nucleotides in length.RNA-encoding constructs that express a single RNA designed to form adsRNA via internal folding are preferably at least about 200 nucleotidesin length.

The promoter used to express the dsRNA-forming construct may be any typeof promoter if the resulting dsRNA is specific for a gene product in thecell lineage targeted for destruction. Alternatively, the promoter maybe lineage specific in that it is only expressed in cells of aparticular development lineage. This might be advantageous where someoverlap in homology is observed with a gene that is expressed in anon-targeted cell lineage. The promoter may also be inducible byexternally controlled factors, or by intracellular environmentalfactors.

In another embodiment, RNA molecules of about 21 to about 23nucleotides, which direct cleavage of specific mRNA to which theycorrespond, as for example described by Tuschl et al. in U.S. Pat. Appl.Pub. No. 20020086356, can be utilised for mediating RNAi. Such 21-23 ntRNA molecules can comprise a 3′ hydroxyl group, can be single-strandedor double stranded (as two 21-23 nt RNAs) wherein the dsRNA moleculescan be blunt ended or comprise overhanging ends (e.g., 5′, 3′).

4. Identification of AT2 receptor antagonists

The invention also features methods of screening for agents thatantagonize an AT₂ receptor, including reducing the expression of an AT₂gene (also known as an Agtr2 gene) or the level and/or functionalactivity of an expression product of that gene. Thus, a candidate agentidentified according to these methods has an ability to reduce thebiological activity or property of an AT₂ receptor polypeptide.

Candidate agents falling within the scope of the present inventioninclude antagonistic antigen-binding molecules, and inhibitor peptidefragments, antisense molecules, ribozymes, RNAi molecules andco-suppression molecules. Other candidate agents include small organiccompounds having a molecular weight of more than 50 and less than about2,500 Dalton and will typically comprise functional groups necessary forstructural interaction with proteins, particularly hydrogen bonding, andtypically include at least an amine, carbonyl, hydroxyl or carboxylgroup, suitably at least two of the functional chemical groups.Candidate agents often comprise cyclical carbon or heterocyclicstructures or aromatic or polyaromatic structures substituted with oneor more of the above functional groups. Candidate agents are also foundamong biomolecules including, but not limited to: peptides, saccharides,fatty acids, steroids, purines, pyrimidines, derivatives, structuralanalogues or combinations thereof.

Small (non-peptide) molecule AT₂ receptor antagonists are generallyadvantageous because such molecules are more readily absorbed after oraladministration, have fewer potential antigenic determinants, or are morelikely to cross the cell membrane than larger, protein-basedpharmaceuticals. Small organic molecules may also have the ability togain entry into an appropriate cell and affect the expression of a gene(e.g., by interacting with the regulatory region or transcriptionfactors involved in gene expression); or affect the activity of a geneby inhibiting or enhancing the binding of accessory molecules.

Alternatively, libraries of natural compounds in the form of bacterial,fungal, plant and animal extracts are available or readily produced.Additionally, natural or synthetically produced libraries and compoundsare readily modified through conventional chemical, physical andbiochemical means, and may be used to produce combinatorial libraries.Known pharmacological agents may be subjected to directed or randomchemical modifications, such as acylation, alkylation, esterification,amidification, etc to produce structural analogues.

Screening may also be directed to known pharmacologically activecompounds and chemical analogues thereof.

In some embodiments, the methods comprise: (1) contacting a preparationwith a test agent, wherein the preparation contains (i) a polypeptidecomprising an amino acid sequence corresponding to at least abiologically active fragment of an AT₂ receptor, or to a variant orderivative thereof; or (ii) a polynucleotide comprising at least aportion of a genetic sequence that regulates an AT₂ gene, which isoperably linked to a reporter gene; and (2) detecting a decrease in thelevel and/or functional activity of the polypeptide, or an expressionproduct of the reporter gene, relative to a normal or reference leveland/or functional activity in the absence of the test agent, whichindicates that the agent antagonizes the AT₂ receptor.

In illustrative examples of this type, the methods comprise the steps ofestablishing a control system comprising an AT₂ receptor polypeptide anda ligand which is capable of binding to the polypeptide; establishing atest system comprising an AT₂ receptor polypeptide, the ligand, and acandidate compound; and determining whether the candidate compoundinhibits or otherwise reduces the functional activity of the polypeptideby comparison of the test and control systems. Representative ligandscan comprise a compound according to any one of formulae and in theseembodiments, the functional activity screened can include bindingaffinity. In certain embodiments, the methods comprise (a) incubating anAT₂ receptor polypeptide with a ligand (e.g., angiotensin II) in thepresence of a test inhibitor compound; (b) determining an amount ofligand that is bound to the AT₂ receptor polypeptide, wherein decreasedbinding of ligand to the AT₂ receptor polypeptide in the presence of thetest inhibitor compound relative to binding in the absence of the testinhibitor compound is indicative of inhibition; and (c) identifying thetest compound as an AT₂ receptor antagonist if decreased ligand bindingis observed. In other embodiments, the methods comprise: (a) incubatinga cell membrane, which comprises an AT₂ receptor polypeptide, with afirst ligand (e.g., angiotensin II) in the presence of a test inhibitorcompound; (b) optionally blocking any AT₁ receptors present on or in themembrane with a second ligand that binds specifically to the AT₁receptor (e.g., losartan or candesartan) if the first ligand also bindsto the AT₁ receptor; (c) determining an amount of first ligand that isbound to the membrane, wherein decreased binding of ligand to themembrane in the presence of the test inhibitor compound relative tobinding in the absence of the test inhibitor compound is indicative ofinhibition; and (d) identifying the test compound as AT₂ receptorantagonist if decreased first ligand binding is observed.

In other illustrative examples, a form of an AT₂ receptor polypeptide ora catalytic or immunogenic fragment or oligopeptide thereof, is used forscreening libraries of compounds in any of a variety of drug screeningtechniques. The fragment employed in such a screening can be affixed toa solid support. The formation of binding complexes, between an AT₂receptor polypeptide and the agent being tested, will be detected. Inspecific embodiments, an AT₂ receptor polypeptide comprises an aminoacid sequence corresponding to any one of:

[SEQ ID NO: 25] MKGNSTLATTSKNITSGLHFGLVNISGNNESTLNCSQKPSDKHLDAIPILYYIIFVIGFLVNIVVVTLFCCQKGPKKVSSIYIFNLAVADLLLLATLPLWATYYSYRYDWLFGPVMCKVFGSFLTLNMFASIFFITCMSVDRYQSVIYPFLSQRRNPWQASYIVPLVWCMACLSSLPTFYFRDVRTIEYLGVNACIMAFPPEKYAQWSAGIALMKNILGFIIPLIFIATCYFGIRKHLLKTNSYGKNRITRDQVLKMAAAVVLAFIICWLPFHVLTFLDALAWMGVINSCEVIAVIDLALPFAILLGFTNSCVNPFLYCFVGNRFQQKLRSVFRVPITWLQGKRESMSCRKSSSLREMETFVS (human AGTR2); [SEQ ID NO: 26]MKDNFSFAATSRNITSSRPFDNLNATGTNESAFNCSHKPSDKHLEAIPVLYYMIFVIGFAVNIVVVSLFCCQKGPKKVSSIYIFNLALADLLLLATLPLWATYYSYRYDWLFGPVMCKVFGSFLTLNMFASIFFITCMSVDRYQSVIYPFLSQRRNPWQASYVVPLVWCMACLSSLPTFYFRDVRTIEYLGVNACIMAFPPEKYAQWSAGIALMKNILGFIIPLIFIATCYFGIRKHLLKTNSYGKNRITRDQVLKMAAAVVLAFIICWLPFHVLTFLDALTWMGIINSCEVIAVIDLALPFAILLGFTNSCVNPFLYCFVGNRFQQKLRSVFRVPITWLQGKRETMSCRKGSSLREMDTFVS (murine AGTR2); and [SEQ ID NO: 27]MKDNFSFAATSRNITSSLPFDNLNATGTNESAFNCSHKPADKHLEAIPVLYYMIFVIGFAVNIVVVSLFCCQKGPKKVSSIYIFNLAVADLLLLATLPLWATYYSYRYDWLFGPVMCKVFGSFLTLNMFASIFFITCMSVDRYQSVIYPFLSQRRNPWQASYVVPLVWCMACLSSLPTFYFRDVRTIEYLGVNACIMAFPPEKYAQWSAGIALMKNILGFIIPLIFIATCYFGIRKHLLKTNSYGKNRITRDQVLKMAAAVVLAFIICWLPFHVLTFLDALTWMGIINSCEVIAVIDLALPFAILLGFTNSCVNPFLYCFVGNRFQQKLRSVFRVPITWLQGKRETMSCRKSSSLREMDTFVS (rat AGTR2).

In still other illustrative examples, a plurality of different smalltest compounds are synthesized on a solid substrate, such as plasticpins or some other surface. The test compounds are reacted with an AT₂receptor polypeptide, or fragments thereof. Bound polypeptide is thendetected by methods well known to those of skill in the art. Thepolypeptide can also be placed directly onto plates for use in theaforementioned drug screening techniques.

In other illustrative examples, the methods comprise: contacting an AT₂receptor polypeptide with individual members of a library of testsamples; detecting an interaction between a test sample and an AT₂receptor polypeptide; identifying a test sample that interacts with anAT₂ receptor polypeptide; and isolating a test sample that interactswith an AT₂ receptor polypeptide.

In each of the foregoing embodiments, an interaction can be detectedspectrophotometrically, radiologically or immunologically. Aninteraction between AT₂ receptor polypeptide and a test sample can alsobe quantified using methods known to those of skill in the art.

In still other embodiments, the methods comprise incubating a cell(e.g., an endothelial cell such as a coronary endothelial cell (CEC), aPC12W cell, a SK-UT-1 cell, a 3T3 fibroblast cell or a NG108-15 cell),which naturally or recombinantly expresses an AT₂ receptor on itssurface, in the presence and absence of a candidate agent underconditions in which the AT₂ receptor is able to bind an AT₂ receptorligand, and the level of AT₂ receptor activation is measured by asuitable assay. For example, an AT₂ receptor antagonist can beidentified by measuring the ability of a candidate agent to decrease AT₂receptor activation in the cell from a baseline value in the presence ofreceptor ligand. In illustrative examples, PC12W cells are exposed to,or cultured in the presence of angiotensin II and in the presence andabsence of the candidate agent under conditions in which the AT₂receptor is active on the cells, and differentiation of the cells ismeasured. An agent tests positive for AT₂ receptor antagonism if itinhibits differentiation of the cells. In other illustrative examples,PC12W cells are exposed to, or cultured in the presence of angiotensinII and in the presence and absence of, the candidate agent underconditions in which the AT₂ receptor is active on the cells, and thelevel of nitric oxide or the level or functional activity of nitricoxide synthase in the cells is measured. An agent tests positive for AT₂receptor antagonism if it inhibits nitric oxide or the level orfunctional activity of nitric oxide synthase. In still otherillustrative examples, coronary endothelial cells are exposed to, orcultured in the presence of angiotensin II and in the presence andabsence of, the candidate agent under conditions in which the AT₂receptor is active on the cells, and expression of Zfhep, which is aprotein associated with cell differentiation, in the cells is measured.An agent tests positive for AT₂ receptor antagonism if it inhibits Zfhepexpression in the cells. In specific embodiments, any AT₁ receptors onthe surface of the cells is blocked using an AT₁ receptor ligand such aslosartan and candesartan.

5. Compositions

Another aspect of the present invention provides compositions fortreating, preventing and/or relieving the symptoms of a neuropathiccondition, comprising an effective amount of an AT₂ receptor antagonistand a pharmaceutically acceptable carrier and/or diluent.

Any known AT₂ receptor antagonist can be used in the methods of thepresent invention, provided that the AT₂ receptor antagonist arepharmaceutically active. A “pharmaceutically active” AT₂ receptorantagonist is in a form which results in the treatment and/or preventionof a neuropathic condition, including the prevention of incurring asymptom, holding in check such symptoms or treating existing symptomsassociated with the neuropathic condition, when administered to anindividual.

The effect of compositions of the present invention may be examined byusing one or more of the published models of pain/nociception or ofneuropathy, especially peripheral neuropathy, and more especiallyneuropathic pain that occurs secondary to mechanical nerve injury or adiabetes-induced nerve injury (PDN), known in the art. This may bedemonstrated, for example using a model which assesses the onset anddevelopment of tactile allodynia, the defining symptom of neuropathicpain, as for example described herein. The analgesic activity of thecompounds of this invention can be evaluated by any method known in theart. Examples of such methods include von Frey filaments (Chaplan etal., 1995, Anesthesiology 83: 775-85. are the Tail-flick test (D'Amouret al. 1941, J. Pharmacol. Exp. and Ther. 72: 74-79); the Rat TailImmersion Model, the Carrageenan-induced Paw Hyperalgesia Model, theFormalin Behavioral Response Model (Dubuisson et al., 1977, Pain 4:161-174), the Von Frey Filament Test (Kim et al., 1992, Pain 50:355-363), the Radiant Heat Model, the Cold Allodynia Model (Gogas etal., 1997, Analgesia 3: 111-118), the paw pressure test (Randall andSelitto, 1957, Arch Int Pharmacodyn 111: 409-419) and the paw thermaltest (Hargreaves et al., 1998, Pain 32: 77-88). An in vivo assay formeasuring the effect of a test compound on the tactile allodyniaresponse in neuropathic rats is described in the Experimental section ofthe Examples. Compositions which test positive in such assays areparticularly useful for the prevention, reduction, or reversal of painin a variety of pain-associated conditions or pathologies includingcancer, and are especially useful for the prevention, reduction, orreversal of neuropathic pain found, for example, in diabetic patients.

The active compounds of the present invention may be provided as saltswith pharmaceutically compatible counterions. Pharmaceuticallycompatible salts may be formed with many acids, including but notlimited to hydrochloric, sulfuric, acetic, lactic, tartaric, malic,succinic, etc. Salts tend to be more soluble in aqueous or otherprotonic solvents that are the corresponding free base forms.

Pharmaceutical compositions suitable for use in the present inventioninclude compositions wherein the pharmaceutically active compounds arecontained in an effective amount to achieve their intended purpose. Thedose of active compounds administered to a patient should be sufficientto achieve a beneficial response in the patient over time such as areduction in at least one symptom associated with a neuropathiccondition, which is suitably neuropathic pain such as diabeticneuropathic pain or neuropathic pain that occurs secondary to nervetrauma or infection. The quantity of the pharmaceutically activecompounds(s) to be administered may depend on the subject to be treatedinclusive of the age, sex, weight and general health condition thereof.In this regard, precise amounts of the active compound(s) foradministration will depend on the judgement of the practitioner. Indetermining the effective amount of the active compound(s) to beadministered in the treatment or prophylaxis of the neuropathiccondition, the physician may evaluate numbness, weakness, pain, and lossof reflexes. In any event, those of skill in the art may readilydetermine suitable dosages of the AT₂ receptor antagonists of theinvention.

An effective amount of an AT₂ receptor antagonist is one that iseffective for the treatment or prevention of a neuropathic condition,including the prevention of incurring a symptom, holding in check suchsymptoms (e.g., pain), and/or treating existing symptoms associated withthe neuropathic condition. Modes of administration, amounts of AT₂receptor antagonist administered, and AT₂ receptor antagonistformulations, for use in the methods of the present invention, arediscussed below. Whether the neuropathic condition has been treated isdetermined by measuring one or more diagnostic parameters indicative ofthe course of the disease, compared to a suitable control. In the caseof an animal experiment, a “suitable control” is an animal not treatedwith the AT₂ receptor antagonist, or treated with the pharmaceuticalcomposition without the AT₂ receptor antagonist. In the case of a humansubject, a “suitable control” may be the individual before treatment, ormay be a human (e.g., an age-matched or similar control) treated with aplacebo. In accordance with the present invention, the treatment of painincludes and encompasses without limitation: (i) preventing painexperienced by a subject which may be predisposed to the condition buthas not yet been diagnosed with the condition and, accordingly, thetreatment constitutes prophylactic treatment for the pathologiccondition; (ii) inhibiting pain initiation or a painful condition, i.e.,arresting its development; (iii) relieving pain, i.e., causingregression of pain initiation or a painful condition; or (iv) relievingsymptoms resulting from a disease or condition believed to cause pain,e.g., relieving the sensation of pain without addressing the underlyingdisease or condition.

The methods of the present invention are suitable for treating anindividual who has been diagnosed with a neuropathic condition, who issuspected of having a neuropathic condition, who is known to besusceptible and who is considered likely to develop a neuropathiccondition, or who is considered likely to develop a recurrence of apreviously treated neuropathic condition.

In some embodiments, and dependent on the intended mode ofadministration, the AT₂ receptor antagonist-containing compositions willgenerally contain about 0.000001% to 90%, about 0.0001% to 50%, or about0.01% to about 25%, by weight of AT₂ receptor antagonist, the remainderbeing suitable pharmaceutical carriers or diluents etc. In someembodiments, a daily dose of the AT₂ receptor antagonist, PD-123,319,may be from about 0.01 to 6000 mg per day, from about 0.02 to 3000 mgper day or from 0.05 to 1500 mg per day. In other embodiments, a dailydose of the AT₂ receptor antagonist, L-159,686, may be from about 0.01to 12000 mg per day, from about 0.02 to 6000 mg per day or from 0.05 to3000 mg per day. In still other embodiments, a daily dose of the AT₂receptor antagonist, PD-121,981, may be from about 0.001 μg to 6000 mgper day, from about 0.002 μg to 3000 mg per day or from 0.005 μg to 1500mg per day. In some embodiments, a daily dose of the AT₂ receptorantagonist, PD-126,055, may be from about 0.001 μg to 100 mg per day,from about 0.002 μg to 50 mg per day or from 0.05 μg to 20 mg per day.In other embodiments, a daily dose of the AT₂ receptor antagonist,L-161,638, may be from about 0.05 μg to 10000 mg per day, from about 0.1μg to 5000 mg per day or from 0.5 μg to 2500 mg per day. In otherembodiments, a daily dose of the AT₂ receptor antagonist, L-163,579, maybe from about 0.001 μg to 3000 mg per day, from about 0.002 μg to 1500mg per day or from 0.005 μg to 750 mg per day. The dosage of the AT₂receptor antagonist can depend on a variety of factors, such as mode ofadministration, the species of the affected subject, age and/orindividual condition, and can be easily determined by a person of skillin the art using standard protocols.

Depending on the specific neuropathic condition being treated, theactive compounds may be formulated and administered systemically,topically or locally. Techniques for formulation and administration maybe found in “Remington's Pharmaceutical Sciences,” Mack Publishing Co.,Easton, Pa., latest edition. Suitable routes may, for example, includeoral, rectal, transmucosal, or intestinal administration; parenteraldelivery, including intramuscular, subcutaneous, intramedullaryinjections, as well as intrathecal, direct intraventricular,intravenous, intraperitoneal, inhaled, intranasal, or intraocularinjections. For injection, the therapeutic agents of the invention maybe formulated in aqueous solutions, suitably in physiologicallycompatible buffers such as Hanks' solution, Ringer's solution, orphysiological saline buffer. For transmucosal administration, penetrantsappropriate to the barrier to be permeated are used in the formulation.Such penetrants are generally known in the art.

Alternatively, the compositions of the invention can be formulated forlocal or topical administration. In this instance, the subjectcompositions may be formulated in any suitable manner, including, butnot limited to, creams, gels, oils, ointments, solutions andsuppositories. Such topical compositions may include a penetrationenhancer such as benzalkonium chloride, digitonin, dihydrocytochalasinB, capric acid, increasing pH from 7.0 to 8.0. Penetration enhancerswhich are directed to enhancing penetration of the active compoundsthrough the epidermis are preferred in this regard. Alternatively, thetopical compositions may include liposomes in which the active compoundsof the invention are encapsulated.

The compositions of this invention may be formulated for administrationin the form of liquids, containing acceptable diluents (such as salineand sterile water), or may be in the form of lotions, creams or gelscontaining acceptable diluents or carriers to impart the desiredtexture, consistency, viscosity and appearance. Acceptable diluents andcarriers are familiar to those skilled in the art and include, but arenot restricted to, ethoxylated and nonethoxylated surfactants, fattyalcohols, fatty acids, hydrocarbon oils (such as palm oil, coconut oil,and mineral oil), cocoa butter waxes, silicon oils, pH balancers,cellulose derivatives, emulsifying agents such as non-ionic organic andinorganic bases, preserving agents, wax esters, steroid alcohols,triglyceride esters, phospholipids such as lecithin and cephalin,polyhydric alcohol esters, fatty alcohol esters, hydrophilic lanolinderivatives, and hydrophilic beeswax derivatives.

Alternatively, the active compounds of the present invention can beformulated readily using pharmaceutically acceptable carriers well knownin the art into dosages suitable for oral administration, which is alsopreferred for the practice of the present invention. Such carriersenable the compounds of the invention to be formulated in dosage formssuch as tablets, pills, capsules, liquids, gels, syrups, slurries,suspensions and the like, for oral ingestion by a patient to be treated.These carriers may be selected from sugars, starches, cellulose and itsderivatives, malt, gelatine, talc, calcium sulfate, vegetable oils,synthetic oils, polyols, alginic acid, phosphate buffered solutions,emulsifiers, isotonic saline, and pyrogen-free water.

Pharmaceutical formulations for parenteral administration includeaqueous solutions of the active compounds in water-soluble form.Additionally, suspensions of the active compounds may be prepared asappropriate oily injection suspensions. Suitable lipophilic solvents orvehicles include fatty oils such as sesame oil, or synthetic fatty acidesters, such as ethyl oleate or triglycerides, or liposomes. Aqueousinjection suspensions may contain substances that increase the viscosityof the suspension, such as sodium carboxymethyl cellulose, sorbitol, ordextran. Optionally, the suspension may also contain suitablestabilizers or agents that increase the solubility of the compounds toallow for the preparation of highly concentrated solutions.

Pharmaceutical preparations for oral use can be obtained by combiningthe active compounds with solid excipients, optionally grinding aresulting mixture, and processing the mixture of granules, after addingsuitable auxiliaries, if desired, to obtain tablets or dragee cores.Suitable excipients are, in particular, fillers such as sugars,including lactose, sucrose, mannitol, or sorbitol; cellulosepreparations such as, for example, maize starch, wheat starch, ricestarch, potato starch, gelatine, gum tragacanth, methyl cellulose,hydroxypropylmethyl-cellulose, sodium carboxymethylcellulose, and/orpolyvinylpyrrolidone (PVP). If desired, disintegrating agents may beadded, such as the cross-linked polyvinyl pyrrolidone, agar, or alginicacid or a salt thereof such as sodium alginate. Such compositions may beprepared by any of the methods of pharmacy but all methods include thestep of bringing into association one or more therapeutic agents asdescribed above with the carrier which constitutes one or more necessaryingredients. In general, the pharmaceutical compositions of the presentinvention may be manufactured in a manner that is itself known, eg. bymeans of conventional mixing, dissolving, granulating, dragee-making,levigating, emulsifying, encapsulating, entrapping or lyophilizingprocesses.

Dragee cores are provided with suitable coatings. For this purpose,concentrated sugar solutions may be used, which may optionally containgum arabic, talc, polyvinyl pyrrolidone, carbopol gel, polyethyleneglycol, and/or titanium dioxide, lacquer solutions, and suitable organicsolvents or solvent mixtures. Dyestuffs or pigments may be added to thetablets or dragee coatings for identification or to characterizedifferent combinations of active compound doses.

Pharmaceuticals which can be used orally include push-fit capsules madeof gelatine, as well as soft, sealed capsules made of gelatine and aplasticiser, such as glycerol or sorbitol. The push-fit capsules cancontain the active ingredients in admixture with filler such as lactose,binders such as starches, and/or lubricants such as talc or magnesiumstearate and, optionally, stabilizers. In soft capsules, the activecompounds may be dissolved or suspended in suitable liquids, such asfatty oils, liquid paraffin, or liquid polyethylene glycols. Inaddition, stabilizers may be added.

Dosage forms of the active compounds of the invention may also includeinjecting or implanting controlled releasing devices designedspecifically for this purpose or other forms of implants modified to actadditionally in this fashion. Controlled release of an active compoundof the invention may be achieved by coating the same, for example, withhydrophobic polymers including acrylic resins, waxes, higher aliphaticalcohols, polylactic and polyglycolic acids and certain cellulosederivatives such as hydroxypropylmethyl cellulose. In addition,controlled release may be achieved by using other polymer matrices,liposomes and/or microspheres.

The active compounds of the invention may be administered over a periodof hours, days, weeks, or months, depending on several factors,including the severity of the neuropathic condition being treated,whether a recurrence of the condition is considered likely, etc. Theadministration may be constant, e.g., constant infusion over a period ofhours, days, weeks, months, etc. Alternatively, the administration maybe intermittent, e.g., active compounds may be administered once a dayover a period of days, once an hour over a period of hours, or any othersuch schedule as deemed suitable.

The compositions of the present invention may also be administered tothe respiratory tract as a nasal or pulmonary inhalation aerosol orsolution for a nebuliser, or as a microfine powder for insufflation,alone or in combination with an inert carrier such as lactose, or withother pharmaceutically acceptable excipients. In such a case, theparticles of the formulation may advantageously have diameters of lessthan 50 micrometers, suitably less than 10 micrometers.

In order that the invention may be readily understood and put intopractical effect, particular preferred embodiments will now be describedby way of the following non-limiting examples.

EXAMPLES Example 1 PD-123,319 Alleviates Neuropathic Pain in Rats with aChronic Constriction Injury (CCI) of the Sciatic Nerve

After administration of single bolus doses of i.v. the AT₂ receptorantagonist, PD-123,319, (0.1-0.3 mg/kg, n=2, FIG. 1) or the i.p. (1-10mg/kg, n=3-4, FIG. 2) route to CCI-rats, there was dose-dependent reliefof tactile allodynia (the defining symptom of neuropathic pain) in theipsilateral (injured) hindpaws and antinociception in the contralateralhindpaws. By contrast, i.p. administration of vehicle (water forinjection) did not produce significant relief of tactile allodynia orantinociception in the ipsilateral or contralateral hindpawsrespectively.

Example 2 L-159,686 Alleviates Neuropathic Pain in CCI-Rats

After administration of single bolus doses of the AT₂ receptorantagonist, L-159,686, (0.1-0.3 mg/kg) by the i.v. (n=2) route toCCI-rats, there was dose-dependent relief of tactile allodynia (thedefining symptom of neuropathic pain) in the ipsilateral (injured)hindpaw and antinociception in the contralateral hindpaw (FIG. 3).

Example 3 PD-123,319 Alleviates Neuropathic Pain in STZ-Diabetic Rats

Following i.p. injection of single bolus doses of PD-123,319 (0.3-3.0mg/kg) to STZ-diabetic rats (n=4) with fully developed tactile allodynia(˜8-wks after induction of diabetes with STZ), there was dose-dependentrelief of tactile allodynia, the defining symptom of painful diabeticneuropathy (FIG. 4). By contrast, i.p. injections of vehicle (water forinjection) did not produce significant relief of tactile allodynia inSTZ-diabetic rats.

Experimental for Examples 1-3 Drugs and Materials

Xylazine hydrochloride (Xylazil-20™), tiletamine HCl/zolazepam HClcombined (Zoletil 100®), and topical antibiotic powder (neomycin sulfate2.5 mg, sulfacetamide sodium 100 mg, nitrofurazone 2 mg, phenylmercuricnitrate 0.05 mg and benzocaine 5 mg, in 50 g soluble powder) werepurchased from Provet Qld Pty Ltd (Brisbane, Australia). Sodiumbenzylpenicillin (Benpen™) was purchased from the Royal BrisbaneHospital Pharmacy (Brisbane, Australia). Isoflurane (lsoflo™) waspurchased from Abbott Australasia (Sydney, Australia), while medicalgrade CO₂ and O₂ were purchased from BOC Gases Ltd. (Brisbane,Australia). Streptozotocin, citric acid and trisodium citrate werepurchased from Sigma-Aldrich (Sydney, Australia). Blood glucose meters(Precision Q.I.D™) and glucose testing electrodes (Precision Plus™) werepurchased from the Campus Pharmacy at The University of Queensland(Brisbane, Australia). Sterile siliconized silk sutures (Dysilk™) wereobtained from Dynek Pty Ltd (Adelaide, South Australia). Single lumenpolyethylene tubing (0.5-mm internal diameter) was purchased fromCritchley Electrical Products Pty Ltd (Auburn, Australia). PD-123,319,as described in U.S. Pat. No. 4,812,462, was synthesized in thelaboratory of Dr Craig Williams, Dept of Chemistry, The University ofQueensland (Brisbane, Australia). L-159,686, as described inInternational Publication No. WO 92/20661, was purchased from ChembridgeCorporation (San Diego, USA).

Rats with a Chronic Constriction Injury (CCI) of the Sciatic Nerve

Adult male Sprague-Dawley (SD) rats were anaesthetized with Zoletil 100®(0.09 ml/200 g) and Xylazil-20™ (0.1 mL/200 g) administered byintraperitoneal (i.p.) injection, and a chronic constriction injury(CCI) of the sciatic nerve was produced according to the method ofBennett and Xie (1988). Briefly, the left common sciatic nerve wasexposed at mid-thigh level by blunt dissection through the bicepsfemoris. Proximal to the trifurcation, 10 mm of nerve was freed ofadhering tissue and four loose ligatures (3.0 silk) were tied around thesciatic nerve 1 mm apart). The incision was closed in layers. Aftersurgery, rats received benzylpenicillin (60 mg s.c.) to preventinfection and were kept warm during surgical recovery. Rats were housedsingly for 10-14 days prior to AT2 receptor antagonist or vehicle(normal saline) administration. After CCI-surgery, rats were inspecteddaily with regard to posture of the affected hindpaw, exploringbehavior, body weight and water intake, and any signs of autotomy.

Induction of Diabetes with Streptozotocin

Adult male SD rats were anaesthetized in a manner similar to thatdescribed above, to facilitate insertion of a polyethylene cannula(previously filled with 0.1 ml of sterile saline) into the right commonjugular vein. Jugular vein cannulae were tested for correct placement bythe withdrawal of a small amount of blood. Diabetes was inducedfollowing an acute i.v. injection of streptozotocin (STZ) (80 mg/kg) in0.1 M citrate buffer (pH 4.5) into the jugular vein. Diabetes wasconfirmed by monitoring the water intake and blood glucose concentrationin individual rats. Blood glucose was monitored using either(Glucostix™) or a Precision QID™ test kit.

Consistent with previous studies in the literature (Calcutt et al.,1996, Pain. 68(2-3):293-9), rats that drank more than 100 mL of waterper day by 10 days post-STZ injection, were classified as diabetic, andonly rats with blood glucose concentrations exceeding 15 mM wereincluded in the subsequent experiments. By comparison, the water intakeof control non-diabetic rats was approximately 20 mL per day and bloodglucose concentrations were in the range 5-6 mM, consistent with theliterature (Calcutt et al., 1996, supra).

Drug Dosing Regimens

Whilst under light anaesthesia with CO₂/O₂ (50:50%), CCI-rats orSTZ-diabetic rats received a single bolus injection (200 μL) of one AT₂receptor antagonist (PD123,319 or L-159,686) by the intravenous (i.v.)or the intraperitoneal (i.p.) route, using a 250 μL Hamilton syringe.The test compounds were administered to CCI-rats at 14 days afterCCI-surgery and to STZ-diabetic rats at approximately 8-wks after theinduction of diabetes with STZ. Relief of tactile (mechanical)allodynia, the defining symptom of neuropathic pain, by each of the testagents, PD123,319 or L-159,686, was quantified using calibrated von Freyfilaments as described below.

Assessment of Antinociception

Tactile allodynia was quantified using calibrated von Frey filaments.Rats were placed in wire mesh testing cages (20 cm×20 cm×20 cm) andallowed to acclimatise for approximately 15-30 min. Von Frey filamentswere used to determine the lowest mechanical threshold required for abrisk paw withdrawal reflex. Briefly, the filament that produced thelowest force was applied to the plantar surface of the hindpaw until thefilament buckled slightly. Absence of a response after 5 s prompted useof the next filament in an ascending sequence. Filaments used produced abuckling weight of 2, 4, 6, 8, 10, 12, 14, 16, 18 and 20 g and thesewere calibrated prior to each testing session. A score of 20 g was givento animals that did not respond to any of the von Frey filaments.

For CCI-rats, baseline von Frey paw withdrawal thresholds (PWTs) werequantified prior to CCI-surgery, and at 14 days post-surgery immediatelyprior to drug administration. For STZ-diabetic rats, baseline von FreyPWT values were determined prior to the induction of diabetes with STZand at 1-2 weekly intervals thereafter for 8 weeks to document thetemporal development of tactile allodynia. For all rats, baseline PWTswere the mean of three readings taken ≈5 min apart before drugadministration and were determined separately for each hindpaw. Afteradministration of each test compound, von Frey PWTs were determined atthe following post-dosing times: 0.08, 0.25, 0.5, 0.75, 1, 1.25, 1.5, 2and 3 h.

Data Analysis

Paw withdrawal thresholds (PWTs; g) were plotted against time toconstruct response versus time curves for each of the two test compounds(PD123,319 and L-159,686) for each dose and dosing route.

Example 4 PD-121,981 Relieves Tactile Allodynia in the STZ-Diabetic RatModel of PDN

After administration of i.p. bolus doses of PD-121,981 (0.001 to 3.0μg/kg) to STZ-diabetic rats, there was dose-dependent relief of tactileallodynia with a rapid onset of action (FIG. 5). Peak anti-allodynia wasachieved at 0.5-1.011 post-dosing. For doses in the range 0.03-3.0μg/kg, the duration of action was >3 h. Consistent with expectations,bolus doses of vehicle did not produce significant anti-allodynia.

Following oral administration of bolus doses of PD-121,981 (0.1 μg/kg)to STZ-diabetic rats, the extent and duration of the anti-allodynicresponse was similar to that produced by the same dose of PD-121,981administered to STZ-diabetic rats by the i.p. route (FIG. 6).Irrespective of dosing route, the duration of action exceeded 3 h (FIG.6).

Example 5 PD-126,055 Relieves Tactile Allodynia in the STZ-Diabetic RatModel of PDN

Administration of i.p. bolus doses of PD-126,055 (1.0 to 100 ng/kg) toSTZ-diabetic rats, produced significant relief of tactile allodynia(FIG. 7). The onset of action was at ˜0.5 h post-dosing and peakanti-allodynia was achieved at ˜0.75-1.0 h post-dosing. For the dosestested, the duration of action was in the range 2-3 h. Consistent withexpectations, bolus doses of vehicle did not produce significantanti-allodynia.

Example 6 Sodium Salt of L-161,638 Relieves Tactile Allodynia in theSTZ-Diabetic Rat Model of PDN

Following i.p. administration of bolus doses of L-161,638 (0.0003 to 3mg/kg) to STZ-diabetic rats, there was a rapid onset of relief oftactile allodynia with peak effects observed at 0.25-0.75 h post-dosing(FIG. 8). For doses in the range 0.0003-0.03 μg/kg, the duration ofaction was ˜3 h. For the 3 mg/kg dose, the duration of action was >3 h.

Example 7 L-163,579 Relieves Tactile Allodynia in the STZ-Diabetic RatModel of PDN

After i.p. administration of bolus doses of L-163,579 (0.1 to 10 μg/kg)to STZ-diabetic rats, there was dose-dependent relief of tactileallodynia characterized by a rapid onset of action (FIG. 9). Peakanti-allodynia was observed at 0.5-1 h post-dosing (FIG. 9) and theduration of action exceeded 3 h for the majority of the doses tested.

Example 8 L-159,686 Relieves Tactile Allodynia in the STZ-Diabetic RatModel of PDN

Following i.p. administration of bolus doses of L-159,686 (0.03 to 10μg/kg) to STZ-diabetic rats, there was dose-dependent relief of tactileallodynia (FIG. 10) but the onset of action was relatively slow withpeak effects occurring at ˜1.25 h post-dosing.

Escalation of the doses to 30 and 100 μg/kg did not produce a fasteronset of action and it did not increase the extent or the duration ofthe anti-allodynic response. For the doses investigated, the duration ofaction was 2-3 h.

Example 9 PD-121,981 Relieves Tactile Allodynia in CCI Rats

Following i.p. administration of bolus doses of PD-121,981 (0.03 to 3mg/kg) in CCI-rats, there was a rapid onset of dose-dependentanti-allodynia in the ipsilateral hindpaw that peaked at 0.5-0.75 hpost-dosing (FIG. 11A). For the doses tested, peak anti-allodynia in theipsilateral hindpaw occurred at 0.5-1.0 h post-dosing and thecorresponding durations of action were 2-3 h. Administration ofPD-121,981 in doses up to 3 mg/kg in CCI -rats produced insignificantantinociception in the contralateral hindpaw (FIG. 11B). Following oraladministration of bolus doses of PD-121,981 (1 mg/kg) to CCI-rats, theextent and duration of the anti-allodynic response was similar to thatproduced by the same dose of PD-121,981 administered to CCI-rats by thei.p. route (FIG. 12). Irrespective of dosing route, the duration ofaction was ˜3 h (FIG. 12).

Example 10 PD-126,055 Relieves Tactile Allodynia in CCI RATS

Bolus i.p. doses of PD-126,055 (3 to 30 μg/kg), or vehicle wereadministered to CCI-rats once tactile allodynia was fully developed inthe ipsilateral (injured) hindpaw. Administration of PD-126,055 in dosesof 3 to 30 μg/kg, produced a rapid dose-dependent onset ofanti-allodynia in the ipsilateral hindpaw (FIG. 13A) with peak responsesobserved at 0.75-1 h post-dosing. The corresponding durations of actionwere 1.5 at the lowest dose tested (3 μg/kg) and >3 h for doses largerthan 3 μg/kg. Administration of PD-126,055 in doses up to 30 μg/kg inCCI-rats produced insignificant antinociception in the contralateralhindpaw (FIG. 13B). Following oral administration of bolus doses ofPD-126,055 (30 μg/kg) to CCI-rats, the extent and duration of theanti-allodynic response was similar to that produced by the same dose ofPD-126,055 administered to CCI-rats by the i.p. route (FIG. 14).Irrespective of dosing route, the duration of action was ˜3 h (FIG. 14).

Example 11 L-161,638 (Sodium Salt) Relieves Tactile Allodynia in CCIRats

Bolus i.p. doses of L-161,638 (0.003 to 10 mg/kg) produced a rapid onsetof dose-dependent anti-allodynia in the ipsilateral hindpaw of CCI-ratswith peak responses observed at 0.5-0.75 h post-dosing (FIG. 15A). Bycontrast, i.p. administration of vehicle produced insignificant reliefof tactile allodynia (FIG. 15A). The corresponding durations of actionwere in the range 1.5-3 h. Administration of L-161,638 in doses up to 10mg/kg in CCI-rats produced insignificant antinociception in thecontralateral hindpaw (FIG. 15B).

Example 12 L-163,579 Relieves Tactile Allodynia in CCI Rats

Bolus i.p. doses of L-163,579 (0.01 to 0.3 mg/kg), or vehicle wereadministered to CCI-rats once tactile allodynia was fully developed inthe ipsilateral (injured) hindpaw. Following administration of L-163,579in doses of 0.01-0.3 mg/kg, there was a rapid onset of anti-allodynia inthe ipsilateral hindpaw (FIG. 16) with peak responses observed at0.25-0.75 h post-dosing. The corresponding durations of action were inthe range 1.5-3 h.

Example 13 L-159,686 Relieves Tactile Allodynia in CCI Rats

Bolus i.p. doses of L-159,686 (0.003 to 0.03 mg/kg) produceddose-dependent relief of tactile allodynia in the ipsilateral (injured)hindpaw of CCI-rats (FIG. 17).

Peak anti-allodynic effects were observed at ˜0.75-1 h post-dosing andfor doses in the range 0.01-0.03 mg/kg, the duration of action was >3 h.

Discussion of Examples 4-13

Single i.p. bolus doses of each of the AT₂ receptor antagonists,PD-121,981, PD126,055, L-161,638 (sodium salt), L-163,579 and L-159,686,produced potent relief of tactile allodynia in the STZ-diabetic ratmodel of PDN. For test articles PD-121,981, PD126,055, L-161,638 (sodiumsalt) and L-163,579, there was a relatively rapid onset ofanti-allodynia with peak responses observed at 0.25-1.0 h post-dosing.For the higher doses of 121,981, PD126,055, L-161,638 (sodium salt) andL-163,579 tested, tactile allodynia in the hindpaws of STZ-diabetic ratswas fully reversed and the corresponding durations of action were 3 h.Single i.p. bolus doses of L-159,686 at 10 μg/kg in STZ-diabetic ratsproduced sub-maximal anti-allodynic responses which were not furtherincreased when the dose was escalated 10-fold to 100 μg/kg.

Interestingly, considerably larger doses of each of PD-121,981,PD126,055, L-161,638 (sodium salt) and L-163,579 were required toproduce significant relief of tactile allodynia in CCI-rats comparedwith STZ-diabetic rats. Thus, despite the fact that CCI- andSTZ-diabetic rat models of neuropathic pain show similar behaviouralsigns, i.e. both groups have fully developed tactile allodynia (thedefining symptom of neuropathic pain), the present findings indicatethat the underlying pathophysiology of these two types of neuropathicpain is quite different. For the majority of the compounds tested, therewas insignificant antinociception produced in the contralateral hindpawindicating that the anti-allodynic responses were produced throughblockade of a target involved in producing the pain response rather thanthrough amplification of the endogenous descending pain inhibitorysystem.

Encouragingly, the mean extent and duration of anti-allodynia producedby oral bolus doses of PD-121,981 (0.1 μg/kg) in STZ-diabetic rats wassimilar to that produced by the same dose administered by the i.p.route. Additionally, the anti-allodynic responses produced by oral bolusdoses of PD-121,981 (1 mg/kg) and PD-126,055 (30 μg/kg) in CCI-rats weresimilar to the responses evoked by the respective doses given by thei.p. route. These observations suggest that PD-121,981 and PD-126,055are not metabolised significantly in the gut wall and they are notsubstrates for P-glycoprotein in the gut wall, but experimentalconfirmation is required.

Experimental for Examples 4-11 Reagents and Materials

Isoflurane (Forthane®) and sodium benzylpenicillin vials were purchasedfrom Abbott Australasia Pty Ltd (Sydney, Australia) and CSL Limited(Melbourne, Australia), respectively. Bupivacaine injection vials werepurchased from Provet Qld Pty Ltd (Brisbane, Australia). Normal salineampoules were obtained from Delta West Pty Ltd (Perth, Australia) andAbbott Australasia (Sydney, Australia). Sterile siliconized silk sutures(Dysilk™) were obtained from Dynek Pty Ltd (Adelaide, South Australia).Single lumen polyethylene tubing (Inner diameter (I.D.) 0.4 mm, Outerdiameter (O.D.) 0.8 mm) was purchased from Auburn Plastics andEngineering Pty Ltd (Sydney, Australia). Medisense® ‘Precision Plus’blood glucose meters were purchased from Abbott Laboratories, (MA, USA).

Test Articles AT₂ Receptor Antagonist Compounds

PD-121,981, as described in U.S. Pat. No. 4,812,462, was synthesized inthe laboratory of Dr Craig Williams, Dept of Chemistry, The Universityof Queensland (Brisbane, Australia). PD-126,055, as described inInternational Publication No. WO 93/23378, was synthesized and suppliedby Industrial Research Limited (IRL) (New Zealand). EMA500, which is thesodium salt of L-161,638 (L-161,638 is described by Glinka et al. 1994,Bioorg. Med. Chem. Lett. 4:1479 and in U.S. Pat. No. 5,204,354), andL-163,579, as described by Glinka et al. (1994, Bioorg. Med. Chem. Lett.4:2337) and in U.S. Pat. No. 5,441,959, were synthesized and supplied byIndustrial Research Limited (IRL) (New Zealand).

Preparation of thiophene-2-carboxylic acidbenzyl-{2-ethyl-4-oxo-3-[2′-(2H-tetrazol-5yl)-biphenyl-4-ylmethyl]-3,4-dihydro-quinazolin-6-yl}-amideSodium Salt

To a solution of L-161,638 [581 mg (95% pure, 5% cyclohexane), 0.884mmol] in methanol (10 mL) and tetrahydrofuran (10 mL) was added sodiumhydroxide (0.882 mL, 0.9976 M, 0.880 mmol). After 30 min at ambienttemperature the volatiles were removed under reduced pressure. Theresultant film was redissolved in water and concentrated under reducedpressure (water bath T=40° C.). The product was freeze dried to giveEMA500 as an off-white powder (571 mg, 0.884 mol, quantitative). m.p.207-211° C.;

C36H28N7NaO2S.2.5H20: requires C, 63.42%; H, 4.73%; N, 14.38%, S, 4.70%.found C, 63.27%; H, 4.80%; N, 14.40%; S, 4.58%; HRMS (ES) C36H28N7O2S(M-) requires 622.2025. found 622.2033.

Animals

Adult male Sprague-Dawley (SD) rats were purchased from the HerstonMedical Research Centre, The University of Queensland. Rats were housedin a temperature controlled environment (21±2° C.) with a 12 h/12 hlight/dark cycle. Food and water were available ad libitum. Rats weregiven an acclimatization period of at least 3 days prior to initiationof experimentation. Ethical approval for these studies was obtained fromthe Animal Experimentation Ethics Committee of The University ofQueensland.

Induction of STZ-Diabetes in Rats and Development of Tactile AllodyniaDiabetes Induction

Whilst adult male SD rats were anaesthetized with 3% isoflurane: 97%oxygen, a short polyethylene cannula (0.4 mm ID, 0.8 mm OD) was insertedinto the jugular vein to facilitate the intravenous (i.v.)administration of a single dose of STZ (75 mg/kg). After removal of thei.v. cannula, the jugular vein was tied off, the wound was closed andtopical bupivacaine was applied. Rats received benzylpenicillin (60 mgs.c.) to prevent infection and were kept warm during surgical recovery.Rats were housed singly prior to further experimentation and weremonitored daily from the time of STZ administration with regard togeneral health and well-being. The diabetes diagnosis was confirmed onday 10 post-STZ administration if blood glucose concentrations were mMwhen measured using a Medisense® device and daily water intake wasgreater than 100 mL.

Tactile Allodynia Development

Calibrated von Frey filaments were used to determine the lowestmechanical threshold required to produce a brisk paw withdrawal reflexin the hindpaws of the rat. Briefly, rats were transferred individuallyto wire mesh testing cages (20 cm×20 cm×20 cm) and allowed toacclimatise for approximately 10-20 min prior to von Frey testing.Commencing with the von Frey filament that produced the lowest force,the filament was applied to the plantar surface of the hindpaw until thefilament buckled slightly. Absence of a response after 5 prompted use ofthe next filament of increasing force. Filaments used produced abuckling weight of 2, 4, 6, 8, 10, 12, 14, 16, 18 and 20 g. A score of20 g was given to animals that did not respond to any of the von Freyfilaments. Before the administration of STZ, baseline von Freymeasurements were assessed. Following STZ administration, baseline vonFrey PWTs were assessed in the hindpaws at periodic intervals to monitorthe development of diabetes-induced tactile allodynia. Tactile allodyniawas fully developed by ˜6-8 wks post-STZ administration when von Freypaw withdrawal thresholds were <6 g; the corresponding pre-diabetic pawwithdrawal thresholds were ˜12 g.

Induction of a Chronic Constriction Injury of the Sciatic Nerve and theDevelopment of Tactile Allodynia Induction of a Chronic ConstrictionInjury (CCI) of the Sciatic Nerve

Whilst adult male SD rats were anaesthetized with 3% isoflurane: 97%oxygen, four loose ligatures were tied around one sciatic nerve toproduce a unilateral chronic constriction injury (CCI) according to themethod of Bennett and Xie (1988, Pain 33: 87-107). Briefly, the leftcommon sciatic nerve was exposed at mid-thigh level by blunt dissectionthrough the biceps femoris. Proximal to the trifurcation, 10 mm of nervewas freed of adhering tissue and four loose ligatures (3.0 silk) weretied around the sciatic nerve 1 mm apart). The incision was closed inlayers. After surgery, rats received benzylpenicillin (60 mg s.c.) toprevent infection and were kept warm during surgical recovery. Rats werehoused singly prior to further experimentation and were monitored dailyfrom the time of CCI-surgery with regard to general health andwell-being.

Tactile Allodynia Development

The time course for the development of tactile allodynia was documentedusing calibrated von Frey filaments. Tactile allodynia was considered tobe fully developed in the ipsilateral (injured) hindpaw when von Freypaw withdrawal thresholds (PWTs) were <6 g; the corresponding PWTs forthe contralateral (non-injured) hindpaw remained unaltered by theCCI-surgery and were ˜12 g. Tactile allodynia was fully developed in theipsilateral hindpaw by ˜10-14 days after CCI-surgery.

Test Article Administration in STZ- and CCI-Rats

Single bolus doses of each of PD-121,981, L-161,638 (sodium salt),L-163,579 and L-159,686 were administered by the intraperitoneal (i.p.)route to groups of STZ-diabetic rats and to groups of CCI-rats inaccordance with a ‘washout’ protocol such that there was at least a 3day washout period between successive bolus doses of the test articlesof interest. Additionally, in a preliminary study, PD-121,981 wasadministered by the oral route to groups of each of STZ-diabetic ratsand CCI-rats.

Assessment of Anti-Allodynic Efficacy

The ability of the test articles of interest to produce dose-dependentrelief of tactile allodynia in groups of STZ- and CCI-rats was assessedusing von Frey filaments pre-dose and at the following post-dosingtimes: 0.25, 0.5, 0.45, 1, 1.25, 1.5, 2, 3 h. The treatment goal was toachieve von Frey PWTs that matched those determined in the same ratsprior to STZ-diabetes induction or prior to CCI-surgery (˜12 g).

The disclosure of every patent, patent application, and publicationcited herein is hereby incorporated herein by reference in its entirety.

The citation of any reference herein should not be construed as anadmission that such reference is available as “Prior Art” to the instantapplication.

Throughout the specification the aim has been to describe the preferredembodiments of the invention without limiting the invention to any oneembodiment or specific collection of features. Those of skill in the artwill therefore appreciate that, in light of the instant disclosure,various modifications and changes can be made in the particularembodiments exemplified without departing from the scope of the presentinvention. All such modifications and changes are intended to beincluded within the scope of the appended claims.

1.-40. (canceled)
 41. A method of treating neuropathic pain in aneuropathy caused by a chemotherapy drug, comprising administering tothe subject an effective amount of an AT₂ receptor antagonist selectedfrom compounds represented by formula (X) or pharmaceutically compatiblesalts thereof:

wherein X is selected from CH or nitrogen; R¹ and R² are independentlyselected from phenyl, substituted phenyl benzyl, substituted benzyl,C₁-C₆alkyl, substituted C₁-C₆alkyl, C₃-C₆cycloalkyl, substitutedC₃-C₆cycloalkyl and heteroaryl; and R⁶ and R⁸ are independently selectedfrom H, C₁₋₆alkyl, substituted C₁-C₆alkyl, C₁-C₆alkoxy, substitutedC₁-C₆alkoxy, phenyl, phenyloxy, benzyl, benzyloxy, benzylamino,biphenyl, substituted biphenyl, biphenyloxy, substituted biphenyloxy,naphthyl, substituted naphthyl, provided that one of R⁶ and R⁸ is nothydrogen.
 42. A method according to claim 41, wherein the AT₂ receptorantagonist, or pharmaceutically compatible salt thereof, is selectedfrom compounds represented by formula (X) wherein R¹ and R² areindependently selected from phenyl or substituted phenyl, X is CH, R⁶ isselected from C₁-C₆alkyl, substituted C₁-C₆alkyl, C₁-C₆alkoxy,substituted C₁-C₆alkoxy, phenyl and phenyloxy and R⁸ is selected fromhydrogen, phenyl, phenyloxy, benzyl, benzyloxy, benzylamino, biphenyl,substituted biphenyl, biphenyloxy, substituted biphenyloxy, naphthyl andsubstituted naphthyl.
 43. A method according to claim 41 wherein atleast one of R¹ and R² is selected from phenyl or substituted phenyl.44. A method according to claim 43 wherein at least one of R¹ and R² isphenyl.
 45. A method according to claim 41 wherein both R¹ and R² areselected from phenyl and substituted phenyl.
 46. A method according toclaim 45 wherein both R¹ and R² are phenyl.
 47. A method according toclaim 41 wherein R⁶ is selected from C₁-C₆alkyl and C₁-C₆alkoxy.
 48. Amethod according to claim 47 wherein R⁶ is C₁-C₃alkoxy.
 49. A methodaccording to claim 48 wherein R⁶ is methoxy.
 50. A method according toclaim 41 wherein R⁸ is selected from benzyl, benzyloxy and benzylamino.51. A method according to claim 50 wherein R⁸ is benzyloxy.
 52. A methodaccording to claim 41 wherein the AT₂ receptor antagonist is2-(diphenylacetyl)-5-benzyloxy-6-methoxy-1,2,3,4-tetrahydroisoquinoline-3-carboxylicacid (PD-126055) or an enantiomer thereof or a pharmaceuticallycompatible salt thereof.
 53. A method according to claim 41 wherein thechemotherapy drug is vincristine.